New Post: Office 2013 Actions Pane and Caliburn Micro

I am trying to use Caliburn Micro as the framework for WPF inside an Excel 2013 Actions Pane, however I am unsure about how this should be done since there is very little documentation on this and I couldn't find much via a web search.

Basically I have referenced the articles on VSTO within Caliburn Micro discussions. So far I have:
1) An Actions Pane added to the Excel document in the ThisWorkbook_Startup method - no problem there.

2) On the design of the Actions Pane, I dropped on a simple ShellView user control

<DockPanel>
        <Label Content="Hello World!" />
        <TabControl x:Name="Items">
            <TabControl.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <TextBlock Text="{Binding DisplayName}" />
                    </StackPanel>
                </DataTemplate>
            </TabControl.ItemTemplate>
        </TabControl>        
    </DockPanel>

3) The ShellViewModel.cs has

public class ShellViewModel : Conductor<IScreen>.Collection.OneActive 
{
        public ShellViewModel()
        {
            ActivateItem(new UploadViewModel());
        }
    }
}

4) I have a MefBootStrapper, derived from BootstrapperBase passing false to the base constructor. The rest is standard MEF bootstrapper code.

5) In the ActionsPane_Load event, I placed a call

new MefBootstrapper().Start();

I see the Hello World! appearing in the Action Pane but there is nothing in the TabControl. The debugger calls the Configure and GetInstance methods of the MefBootstrapper.

If I remove the ShellView user control from the design surface and change the ShellView.xaml to be a Window instead of a user control, it is no longer listed in the Visual Studio toolbox as a control and I can't drop it onto the design surface. Adding the following code in the Actions Pane load event does not cause the ShellView to show up.

            var windowManager = IoC.Get<IWindowManager>();
            windowManager.ShowWindow(new ShellViewModel());

All code is in a single solution. Has anyone tried this who can point me in the right direction.