diff --git a/StarterNG/Classes/AppState.cs b/StarterNG/Classes/AppState.cs
index fbbdf0a..624fc14 100644
--- a/StarterNG/Classes/AppState.cs
+++ b/StarterNG/Classes/AppState.cs
@@ -1,4 +1,6 @@
-namespace StarterNG.Classes;
+using System;
+
+namespace StarterNG.Classes;
 
 /// <summary>
 /// Shared selection state across views: the scenery and trainset currently in
@@ -10,6 +12,50 @@ public sealed class AppState
 {
     public static AppState Instance { get; } = new();
 
-    public Scenery? CurrentScenery { get; set; }
-    public Trainset? CurrentTrainset { get; set; }
+    public event Action? Changed;
+
+    private Scenery? _currentScenery;
+    private Trainset? _currentTrainset;
+    private string? _startingVehicleName;
+
+    public Scenery? CurrentScenery
+    {
+        get => _currentScenery;
+        set
+        {
+            if (ReferenceEquals(_currentScenery, value)) return;
+            _currentScenery = value;
+            Changed?.Invoke();
+        }
+    }
+
+    public Trainset? CurrentTrainset
+    {
+        get => _currentTrainset;
+        set
+        {
+            if (ReferenceEquals(_currentTrainset, value)) return;
+            _currentTrainset = value;
+            Changed?.Invoke();
+        }
+    }
+
+    /// <summary>
+    /// Node name of the vehicle the player starts in (<c>-v</c>), like Pascal
+    /// <c>SelVehicle</c>. Updated when a consist car is clicked in the depot or a
+    /// trainset is picked in Scenarios.
+    /// </summary>
+    public string? StartingVehicleName
+    {
+        get => _startingVehicleName;
+        set
+        {
+            if (_startingVehicleName == value) return;
+            _startingVehicleName = value;
+            Changed?.Invoke();
+        }
+    }
+
+    /// <summary>Notify listeners after in-place edits that affect Start enablement.</summary>
+    public void NotifyChanged() => Changed?.Invoke();
 }
diff --git a/StarterNG/MainWindow.axaml b/StarterNG/MainWindow.axaml
index 8cbddeb..80decfc 100644
--- a/StarterNG/MainWindow.axaml
+++ b/StarterNG/MainWindow.axaml
@@ -70,9 +70,9 @@
                                      Tag="settings"
                                      IsCheckedChanged="Nav_OnCheckedChanged"
                                      Content="{Binding [NavSettings], Source={x:Static starterNg:App.Loc}}" />
-                        <Button Classes="Basic" Width="48" Cursor="Hand"
+                        <Button x:Name="HelpButton" Classes="Basic" Width="48" Cursor="Hand"
                                 ToolTip.Tip="{Binding [Help], Source={x:Static starterNg:App.Loc}}"
-                                Tag="https://wiki.eu07.pl/" Click="linkClick"
+                                Click="HelpButton_OnClick"
                                 Content="?" FontWeight="Bold" FontSize="16"
                                 HorizontalContentAlignment="Center" />
                     </StackPanel>
@@ -88,11 +88,8 @@
                                    FontSize="10" Foreground="{StaticResource CarbonFg}" Padding="0" />
                         </StackPanel>
 
-                        <ComboBox x:Name="LangCombo" Width="100" VerticalAlignment="Center"
-                                  SelectionChanged="LangCombo_OnSelectionChanged">
-                            <ComboBoxItem>Polski</ComboBoxItem>
-                            <ComboBoxItem>English</ComboBoxItem>
-                        </ComboBox>
+                        <ComboBox x:Name="LangCombo" Width="110" VerticalAlignment="Center"
+                                  SelectionChanged="LangCombo_OnSelectionChanged" />
 
                         <Button Classes="Basic" Cursor="Hand" Tag="http://eu07.pl/" Click="linkClick">
                             <materialIcons:MaterialIcon Kind="Web" />
@@ -115,7 +112,7 @@
         </Border>
 
         <!-- ── Full-width START button (bottom) ─────────────────────────────── -->
-        <Button DockPanel.Dock="Bottom" Classes="Start" Height="44" Margin="6"
+        <Button Name="startButton" DockPanel.Dock="Bottom" Classes="Start" Height="44" Margin="6"
                 Click="StartButton_OnClick"
                 Content="{Binding [Start], Source={x:Static starterNg:App.Loc}}" />
 
diff --git a/StarterNG/MainWindow.axaml.cs b/StarterNG/MainWindow.axaml.cs
index 69c9c0e..9640373 100644
--- a/StarterNG/MainWindow.axaml.cs
+++ b/StarterNG/MainWindow.axaml.cs
@@ -9,11 +9,20 @@ using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Threading;
 using StarterNG.Classes;
+using StarterNG.Domain;
+using StarterNG.Infrastructure;
+using StarterNG.Services;
+using StarterNG.Views;
+using SettingsModel = StarterNG.Classes.Settings;
 
 namespace StarterNG;
 
 public partial class MainWindow : Window
 {
+    // Tracks Ctrl for Start bypass (Pascal btnStart.Tag while Ctrl held).
+    private KeyModifiers _mods;
+    private DateTime _openedUtc = DateTime.UtcNow;
+
     public MainWindow()
     {
         Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
@@ -29,8 +38,23 @@ public partial class MainWindow : Window
         // buttons fill this height at the top-right, sitting above the social row.
         ExtendClientAreaTitleBarHeightHint = 32;
 
-        // Mirror the active language into the top-bar selector.
-        LangCombo.SelectedIndex = App.Loc.CurrentLanguage == "Polski" ? 0 : 1;
+        PopulateLangCombo();
+
+        // Keep Start enabled/caption in sync with selection (Pascal actStartUpdate).
+        AppState.Instance.Changed += UpdateStartButton;
+        Opened += (_, _) =>
+        {
+            _openedUtc = DateTime.UtcNow;
+            UpdateStartButton();
+        };
+        Activated += (_, _) => CheckExternalSettings();
+        AddHandler(InputElement.KeyDownEvent, (_, e) => { _mods = e.KeyModifiers; UpdateStartButton(); }, handledEventsToo: true);
+        AddHandler(InputElement.KeyUpEvent, (_, e) => { _mods = e.KeyModifiers; UpdateStartButton(); }, handledEventsToo: true);
+        AddHandler(InputElement.PointerMovedEvent, (_, e) =>
+        {
+            var m = e.KeyModifiers;
+            if (m != _mods) { _mods = m; UpdateStartButton(); }
+        }, handledEventsToo: true);
     }
 
     // Lets the user drag the window by the top caption strip.
@@ -56,13 +80,70 @@ public partial class MainWindow : Window
         SettingsView.IsVisible = page == "settings";
     }
 
+    private void PopulateLangCombo()
+    {
+        LangCombo.Items.Clear();
+        int selected = 0;
+        var langs = LocalizationService.AvailableLanguages();
+        if (langs.Count == 0)
+        {
+            LangCombo.Items.Add(new ComboBoxItem { Content = "English" });
+            LangCombo.SelectedIndex = 0;
+            return;
+        }
+        for (int i = 0; i < langs.Count; i++)
+        {
+            LangCombo.Items.Add(new ComboBoxItem { Content = langs[i].Name, Tag = langs[i].Code });
+            if (string.Equals(langs[i].Name, App.Loc.CurrentLanguage, StringComparison.OrdinalIgnoreCase) ||
+                string.Equals(langs[i].Code, App.Loc.CurrentLangCode, StringComparison.OrdinalIgnoreCase))
+                selected = i;
+        }
+        LangCombo.SelectedIndex = selected;
+    }
+
     private void LangCombo_OnSelectionChanged(object? sender, SelectionChangedEventArgs e)
     {
         if (sender is not ComboBox { SelectedItem: ComboBoxItem item }) return;
         if (!item.IsKeyboardFocusWithin) return; // ignore the programmatic initial set
-        var lang = item.Content?.ToString();
+        var lang = item.Tag as string ?? item.Content?.ToString();
         if (!string.IsNullOrEmpty(lang))
+        {
             App.ApplyLanguage(lang);
+            ScenariosView?.RebuildAfterLanguageChange();
+        }
+    }
+
+    private void HelpButton_OnClick(object? sender, RoutedEventArgs e)
+    {
+        var menu = new ContextMenu();
+
+        var wiki = new MenuItem { Header = App.Loc["HelpWiki"] };
+        wiki.Click += (_, _) => OpenPathOrUrl("https://wiki.eu07.pl/");
+        menu.Items.Add(wiki);
+
+        string readme = string.Equals(App.Loc.CurrentLangCode, "pl", StringComparison.OrdinalIgnoreCase)
+            ? "readme.html" : "en-readme.html";
+        if (File.Exists(readme) || File.Exists(Path.Combine(Directory.GetCurrentDirectory(), readme)))
+        {
+            var mi = new MenuItem { Header = App.Loc["HelpReadme"] };
+            mi.Click += (_, _) => OpenPathOrUrl(readme);
+            menu.Items.Add(mi);
+        }
+
+        string regs = Path.Combine(Directory.GetCurrentDirectory(), "przepisy_kolejowe");
+        if (Directory.Exists(regs))
+        {
+            menu.Items.Add(new Separator());
+            foreach (string pdf in Directory.GetFiles(regs, "*.pdf").OrderBy(Path.GetFileName))
+            {
+                string file = pdf;
+                var mi = new MenuItem { Header = Path.GetFileName(file) };
+                mi.Click += (_, _) => OpenPathOrUrl(file);
+                menu.Items.Add(mi);
+            }
+        }
+
+        menu.Open(HelpButton);
     }
 
     private void linkClick(object? sender, RoutedEventArgs e)
@@ -73,10 +154,23 @@ public partial class MainWindow : Window
         if (btn.Tag is not string url || string.IsNullOrWhiteSpace(url))
             return;
 
-        Process.Start(new ProcessStartInfo(url)
+        OpenPathOrUrl(url);
+    }
+
+    private static void OpenPathOrUrl(string pathOrUrl)
+    {
+        try
         {
-            UseShellExecute = true
-        });
+            string target = pathOrUrl;
+            if (!pathOrUrl.StartsWith("http", StringComparison.OrdinalIgnoreCase))
+            {
+                target = Path.GetFullPath(pathOrUrl);
+                if (!File.Exists(target) && !Directory.Exists(target))
+                    return;
+            }
+            Process.Start(new ProcessStartInfo(target) { UseShellExecute = true });
+        }
+        catch { }
     }
 
     private void openLastLogClick(object? sender, RoutedEventArgs e)
@@ -91,6 +185,55 @@ public partial class MainWindow : Window
         }
     }
 
+    // Pascal actStartUpdate: Start needs scenery + trainset + staffed/passenger
+    // vehicle. Hold Ctrl to force START (bypass crew check).
+    private void UpdateStartButton()
+    {
+        if (startButton is null) return;
+
+        var scenery = AppState.Instance.CurrentScenery;
+        var trainset = AppState.Instance.CurrentTrainset;
+        bool ctrl = _mods.HasFlag(KeyModifiers.Control);
+
+        if (scenery is null)
+        {
+            startButton.Content = App.Loc["StartNoScenery"];
+            startButton.IsEnabled = false;
+            return;
+        }
+        if (trainset is null)
+        {
+            startButton.Content = App.Loc["StartNoTrain"];
+            startButton.IsEnabled = false;
+            return;
+        }
+        if (!HasStartableVehicle(trainset) && !ctrl)
+        {
+            startButton.Content = App.Loc["StartNoStaff"];
+            startButton.IsEnabled = false;
+            return;
+        }
+
+        startButton.Content = App.Loc["Start"];
+        startButton.IsEnabled = true;
+    }
+
+    private static bool HasStartableVehicle(Trainset trainset)
+    {
+        static bool CanStart(Dynamic v) =>
+            v.DriverType is eDriverType.Headdriver or eDriverType.Reardriver or eDriverType.Passenger;
+
+        string? selected = AppState.Instance.StartingVehicleName;
+        if (!string.IsNullOrEmpty(selected))
+        {
+            var pick = trainset.Vehicles.FirstOrDefault(v =>
+                string.Equals(v.Name, selected, StringComparison.OrdinalIgnoreCase));
+            if (pick != null)
+                return CanStart(pick);
+        }
+        return trainset.Vehicles.Any(CanStart);
+    }
+
     // ── START: export the (possibly depot-modified) scenery and launch the sim.
     // Global on the main window, like the original Starter's bottom START button.
     private void StartButton_OnClick(object? sender, RoutedEventArgs e)
@@ -99,10 +242,15 @@ public partial class MainWindow : Window
         if (scenery is null)
             return;
         var trainset = AppState.Instance.CurrentTrainset;
+        if (trainset is null)
+            return;
 
-        if (trainset is { Vehicles.Count: > 0 })
+        if (!HasStartableVehicle(trainset) && !_mods.HasFlag(KeyModifiers.Control))
+            return;
+
+        if (trainset.Vehicles.Count > 0)
         {
-            trainset.Velocity = Settings.Instance.BatteryDefault switch
+            trainset.Velocity = SettingsModel.Instance.BatteryDefault switch
             {
                 BatteryDefault.AlwaysOff => 0f,
                 BatteryDefault.AlwaysOn  => MathF.Abs(trainset.OriginalVelocity) < 0.01f ? 0.1f : trainset.OriginalVelocity,
@@ -110,26 +258,34 @@ public partial class MainWindow : Window
             };
         }
 
+        // Pascal UniqueVehicleName / UniqueVehiclesName before writing $scn.
+        string? vehicle = TrainsetDisplay.UniquifyForLaunch(
+            trainset, scenery, AppState.Instance.StartingVehicleName);
+        if (string.IsNullOrEmpty(vehicle))
+            vehicle = ResolveStartVehicle(trainset);
+        AppState.Instance.StartingVehicleName = vehicle;
+
+        LoadingScreen.Prepare(trainset.Logo, Path.GetFileNameWithoutExtension(scenery.Path));
+
+        // Always inject the Weather-tab values (incl. start-time override), like the
+        // Pascal starter's ChangeConfig on every launch — not only after an edit.
+        scenery.WeatherDirty = true;
+
         // write scenery/$<name>.scn with the replaced trainsets
         string dir = Path.GetDirectoryName(scenery.Path) ?? "scenery";
         string exportName = "$" + Path.GetFileName(scenery.Path);
         string exportPath = Path.Combine(dir, exportName);
         try
         {
-            File.WriteAllText(exportPath, scenery.BuildExportContent(Settings.Instance.IgnoreIrrelevantTrains), Encoding.GetEncoding(1250));
+            File.WriteAllText(exportPath, scenery.BuildExportContent(SettingsModel.Instance.IgnoreIrrelevantTrains), Encoding.GetEncoding(1250));
         }
         catch
         {
             return; // couldn't write the scenery file
         }
 
-        // the player's vehicle is the node name of the driven car in the consist
-        string? vehicle = trainset?.Vehicles
-            .FirstOrDefault(v => v.DriverType is eDriverType.Headdriver or eDriverType.Reardriver)?.Name
-            ?? trainset?.Vehicles.FirstOrDefault()?.Name;
-
         // make sure the latest settings are on disk before the sim reads them
-        Settings.Instance.CaptureAndSave();
+        SettingsModel.Instance.CaptureAndSave();
 
         // launch the game: -s $<name>.scn -v <vehicle>. Keep the handle so we can
         // watch for the simulator exiting. UseShellExecute = false runs the binary
@@ -138,7 +294,7 @@ public partial class MainWindow : Window
         Process? sim;
         try
         {
-            string exe = Path.GetFullPath(Settings.Instance.ResolveExecutable());
+            string exe = Path.GetFullPath(SettingsModel.Instance.ResolveExecutable());
             sim = Process.Start(new ProcessStartInfo
             {
                 FileName = exe,
@@ -153,7 +309,7 @@ public partial class MainWindow : Window
         }
 
         // honour the "close starter automatically" preference
-        if (Settings.Instance.AutoCloseStarter)
+        if (SettingsModel.Instance.AutoCloseStarter)
         {
             Close();
             return;
@@ -170,6 +326,29 @@ public partial class MainWindow : Window
         WatchSimulator(sim);
     }
 
+    // Pascal: RunInfo.Vehicle := Train.Vehicles[SelVehicle].Name after actStartUpdate
+    // requires headdriver/reardriver/passenger on that car.
+    private static string? ResolveStartVehicle(Trainset? trainset)
+    {
+        if (trainset is null || trainset.Vehicles.Count == 0)
+            return null;
+
+        static bool CanStart(Dynamic v) =>
+            v.DriverType is eDriverType.Headdriver or eDriverType.Reardriver or eDriverType.Passenger;
+
+        string? selected = AppState.Instance.StartingVehicleName;
+        if (!string.IsNullOrEmpty(selected))
+        {
+            var pick = trainset.Vehicles.FirstOrDefault(v =>
+                string.Equals(v.Name, selected, StringComparison.OrdinalIgnoreCase));
+            if (pick != null && CanStart(pick))
+                return pick.Name;
+        }
+
+        return trainset.Vehicles.FirstOrDefault(CanStart)?.Name
+               ?? trainset.Vehicles.FirstOrDefault()?.Name;
+    }
+
     // Waits (off the UI thread) for the simulator to exit, then restores the
     // starter window. Uses the launch handle when available, otherwise locates the
     // process by name, and never leaves the UI hidden if it cannot be tracked.
@@ -177,7 +356,7 @@ public partial class MainWindow : Window
     {
         if (sim is null)
         {
-            string name = Path.GetFileNameWithoutExtension(Settings.Instance.ResolveExecutable());
+            string name = Path.GetFileNameWithoutExtension(SettingsModel.Instance.ResolveExecutable());
             sim = Process.GetProcessesByName(name).FirstOrDefault();
         }
 
@@ -201,6 +380,28 @@ public partial class MainWindow : Window
         watcher.Start();
     }
 
+    // Pascal CheckSettingsFile on AppActivate (skip the first few seconds).
+    private async void CheckExternalSettings()
+    {
+        if ((DateTime.UtcNow - _openedUtc).TotalSeconds < 3)
+            return;
+        if (!SettingsModel.Instance.IsConfigNewerOnDisk())
+            return;
+
+        var result = await MessageBox.Show(
+            this,
+            App.Loc["SettingsFileChanged"],
+            App.Loc["SettingsFileChangedTitle"],
+            MessageBoxButtons.YesNo);
+        if (result)
+        {
+            SettingsModel.Instance.Load();
+            SettingsView?.ReloadFromSettings();
+        }
+        else
+            SettingsModel.Instance.TouchConfigAge();
+    }
+
     // Brings the starter back to the foreground after the simulator closes.
     private void RestoreFromSimulator()
     {
diff --git a/StarterNG/Views/MessageBox.cs b/StarterNG/Views/MessageBox.cs
new file mode 100644
index 0000000..091e026
--- /dev/null
+++ b/StarterNG/Views/MessageBox.cs
@@ -0,0 +1,56 @@
+using System.Threading.Tasks;
+using Avalonia.Controls;
+using Avalonia.Layout;
+using Avalonia.Media;
+
+namespace StarterNG.Views;
+
+public enum MessageBoxButtons
+{
+    YesNo
+}
+
+public static class MessageBox
+{
+    /// <summary>Simple Yes/No dialog. Returns true for Yes.</summary>
+    public static async Task<bool> Show(Window owner, string message, string title, MessageBoxButtons _)
+    {
+        var win = new Window
+        {
+            Title = title,
+            Width = 420,
+            SizeToContent = SizeToContent.Height,
+            WindowStartupLocation = WindowStartupLocation.CenterOwner,
+            CanResize = false
+        };
+
+        bool yes = false;
+        var yesBtn = new Button { Content = App.Loc["Yes"], MinWidth = 80, Cursor = new Avalonia.Input.Cursor(Avalonia.Input.StandardCursorType.Hand) };
+        yesBtn.Classes.Add("Accent");
+        yesBtn.Click += (_, _) => { yes = true; win.Close(); };
+
+        var noBtn = new Button { Content = App.Loc["No"], MinWidth = 80, Cursor = new Avalonia.Input.Cursor(Avalonia.Input.StandardCursorType.Hand) };
+        noBtn.Classes.Add("Flat");
+        noBtn.Click += (_, _) => win.Close();
+
+        win.Content = new StackPanel
+        {
+            Margin = new Avalonia.Thickness(16),
+            Spacing = 16,
+            Children =
+            {
+                new TextBlock { Text = message, TextWrapping = TextWrapping.Wrap },
+                new StackPanel
+                {
+                    Orientation = Orientation.Horizontal,
+                    HorizontalAlignment = HorizontalAlignment.Right,
+                    Spacing = 8,
+                    Children = { yesBtn, noBtn }
+                }
+            }
+        };
+
+        await win.ShowDialog(owner);
+        return yes;
+    }
+}