I'm sure if you worked with a local shop you could peice together something similiar or rebuild the originals. I think megabite had the right idea. you could always pull the old ones apart and use them as a template for a new structure.
just like anything on an old boat, its not a matter of can it be fixed, its a matter of how much do you want to pay.
If it makes you feel any better I get the joy of trying to figure out a way of reupholestring the rear bench seat and back and having it match the perfectly good sundeck and buckets. for some reason only the rear bench is shot everything else is in excellent condition, I have no idea why.