A bare 40 coupe body can be lifted by 4-6 guys.
I'd guess it was ~350-400 pounds.
If the floor and rockers are okay, a good 4X4 frame with casters that fits the main floor area should do it. I also supported it with just a 4X4 at the front (under the forward edge of the door area) and another under the rear wheelwell area.
If the body is all rotted on the bottom, you will want more support. A rotissere won't work well on a bare body without some special supports up front.