Re: Cover over gas tank, should it be soft?
 

My son repaired the hatch over the fuel tank of my '86 last year. One piece of 1/2 inch plywood, glassed in, worked just fine. Be sure to take the wood as close to the edges of the hatch as you can. Otherwise, it will continue to flex. This year we did the hatch over the fish well between the pedestal seats. Good luck.