Mike,
That seat looks nice. The parts Im talking about can be bought new. The spring is called flex-o-lators comes in different widths.Then you put little coils in back. You need to do alot of drilling on frame. Then the foam can be cut to fit your seat. With your seat being already upholstered I would do as you originally stated try to find the original springs. Just asking did you do a AuVeCo search. They used to have them. Good luck in your search. Seen them on Ebay one time. Again nice looking seat. Tom 573 883 6242
