Host WPF User Control within Windows Form UserControl

Question

I have created a Windows Form UserControl (TabControl) and a WPF UserControl.  I need the WPF UserControl added to the Windows Form UserControl.

 

I know how to add a WPF UserControl onto a Windows Form, but need to add a WPF UserControl to a Windows UserControl.  I cannot use a Windows Form due to application restrictions for which the Plugin is being developed.

 

If I try and use an ElementHost, the WPF Control is simply not displayed when the plugin loads.  I have tested adding some native Windows Form controls and this works.

Any ideas gratefully received