Boyd,
I started my Bennett car in 1992 and still have it. The body was Butler based and Paul was a partner on the mold. The first body I picked up at the fiberglass house, which was in Hayward, Ca had excessive shrinkage. Paul’s bodies were almost twice as thick as others were at that time. Later, I returned it for another, which I kept. Due to the partnership issues no other molds were made. The hood, trunk and doors came from another supplier in L.A.
Anyway, Paul designed his space frame chassis to fit in the "standard" Cobra body. Since the frame utilizes 2" main tubes you sit two inches lower in the car, this makes the body short on the sides. I made some 'glass skirts to extend the body downward (between the wheell wells) to wrap around and under the outer frame rails.
I would not be afraid to try the most universal body you can find out there, after all, it is 'glass cut or add to it as needed. The frame design dictates aluminum inner panels throughout. Let me know if you need more info.
Jeff