I haven't had EXACTLY this happen to me, but I had something a little similar with an old car I had in the 80s. I had part of the seat frame break due to stress from repeated "pushing back" on the seat back. You could never sit square-on to the steering wheel, and it was aggravating as all get-out.
I unbolted the seat and took off the back. (It was still covered with vinyl.) I brought it to a guy with some welding equipment, and he stuffed all sorts of wet rags around the break to protect the burlap jute, the foam, and the vinyl from the heat. He was able to weld the steel frame without damaging the heat-sensitive items. This might be the fix for your components that separated.
You'll probably still need to replace the sprung springs, though. You have nothing to lose by trying to heat them into shape, but seldom will the results be like the original.
You might consider contacting Jimbo59Chevy. He has some '50 - '59 stovebolts that he parts out. (I got an air cleaner from him. Nice fella.) He has a torch and could probably cut you a section of the seat springs. Your welder contact might be able to put it back into form.
I hope this info helps. It ain't much, but it's all I have.
Bill
