Re: how to get back of seats off to recloth
DON'T start ripping and tearing your seat backs off just yet. Try these first:
1) Grab the bottom edge and run your fingers around the bottom perimeter of the cushion. Sometimes there are small tabs screwed into the backs of the cushions and then into the gel coat to hold them in place. This is most common on "slip-on" backs, which rest on Z shaped tabs. If you find the screws, remove them and briskly pull upon the back to release it from the hangers. Some are put on the hangers without the retaining screws. Try pulling up first.
2) Look closely at the bottom edge of the vinyl, just in front of the edge of the plywood. Some manufacturers simply make tiny slits in the vinyl and run the screws thru the plywood & into the boat. The bottom edge is hidden, so most people don't notice.
3) If they are multi colored backs or have areas of vinyl tucked into the creases, open there and look for retaining screws and/or slits in the vinyl.
4) After removing the seats, there may be room to reach your hand up behind the seats. Feel for small nuts and washers (usually 7/16") which are attached to bolts coming from the seat backs.
LAST course of action is to cut open the vinyl and look for attachments. That usually ruins the foam or at least makes for more work gluing it back together.
PM if you need more help.