: I've decided that the best seats
: are hard, the best poly and fiberglass seats seem to be the most
: comfy.
: Bill H.
You can build a fiberglass seat. You don't need a mold, use the moldless composite construction. This is where you carve the shape that you want using styrofoam, then just glass over the foam leaving it in place. This is how early fiberglass surfboards were made. Styrofoam has enough strength that you can use if a couple if times before glassing to make sure the shape is right. Buoyancy foam is stryofoam, the stuff you put under floating docks.

The nice thing about moldless construction is if it doesn't come out right you can just cut out the offending part, build up the shape again with foam-in-place, then glass it again.