I have tried your scenario and adding the dlls manually did the trick for me.
I have shot a short movie
of my actions:
1. Create a new WPF project
2. Drag a control from the toolbox onto the design surface
3. In the references folder manually add the dlls which are needed for the control that you have dragged onto the design surface
4. Rebuild the solution
Can you please see the movie and tell me how to reproduce the behavior that you are experiencing on your end.
the Telerik team