Ok, OI, those are pretty good pictures, and from what I can see it looks like the inner structure ( most of it wood) has gone away, leaving only sheet metal that has no strength to retain it's shape.
What I would do is get the body off the frame, set it on the floor, and start taking measurements and determining what it would take to get it back to what it should look like. Then, you can build a temporary inner structure to pull it all back into shape and then see what you will need to fabricate to make it strong and retain it's original dimensions.
These early Ford bodies were just a skin, shaped by (usually) a wooden framework screwed to it. Roadster bodies are especially prone to losing their shape as the inner structure rots or rust out, as there is no roof to hold all the pieces together.
So, yes, I would get the body removed while keeping it as intact as possible, then tack weld some tubing inside and across it to start pulling it into shape. Then you can build your inner structure to permanently keep that shape, and things like the floor being welded in will really help that a lot.
A lot of cross bracing, a lot of C clamps, turnbuckles and cables, and vice grips, and you will begin to see it pull back into shape. Start at the cowl, as that part is generally able to keep it's original shape, and work rearward, one panel at a time.