For the hatch repair.
We still use fiberglass mat for reinforcement, but we don't use resin. We use a product from Lord called Fusor. In my opinion it is far superior to resin. We use it on everything from Corvettes to heavy duty truck hoods.
My son in law just did a major repair on a hatch, cutting it all apart and repairing stress points and hinges with fiberglass mat and Fusor.
He also cut the "droopy" top skin off shaped it with expanding foam, and glued the skin back on with Fusor.
https://www.lord.com/products-and-so...pair-adhesives