Hi Alan Day,
The Design View is actually in a split container with the source code, but the button that displays the design view as well as the swap panes buttons are missing . So you can try resizing the split containers below the design viewer that holds the xaml as shown on the attachment.
In expression blend you should use the Assets menu to navigate to the controls. Please get back to us if you need further details.
All the best,
the Telerik team