That's a whole lot more work than you think.

James Sweet wrote:
jamesgangnc wrote:
I've had very little success with that solution myself. The repaired
piece still has a significantly different strength at the site of the
repair. Plastics flexes when loaded. Repairing it this way just
further stiffens the surrounding area and concentrates even more of the
load on the repaired area which is now far and away the weakest point
in the structure. It breaks again at the same spot usually pretty
quickly.

I'd suggest searcching for some of the boat "junkyards" online and
trying to buy an old seat from them. Then transfer your foam and
ulpholstery. I did that with one of the bucket seat in my boat.




How about using the glued together seat to make a mold to build a new
one out of fiberglass?