Afternoon David,
There's not very much info on this one, so I'm not sure about the engine, the photos do show a rather large diameter, but not very long engine of some sort, I suspect that as the photos are of a model, it may have been a ducted-fan unit and possibly not representative of the final installation.
It was indeed a product of his post-war years in the USA working for established companies.
Edit: It was to be a radio controlled interceptor!
The canards are also very highly swept
Not so, that is an illusion caused by very large dihedral angle.