Fiberglass hood repair/correction question
I had the same issue on a Challenger hood and what I did was ground the underside down thin. I then took a piece of 2"x 1/8" aluminum flat stock and bent it to the contour of the fender.
Drill through the hood and flatstock in a couple of locations and install rivets through the hood into the flat stock with JB weld between the two.
Make sure the contour is correct by installing the hood. Grind the rivets off protruding through the flat stock and put desired amount of fiberglass cloth and resin over the aluminum stock. Then grind off the rivets on the outside of the hood and cover them with resin.
Heating the hood will not work. That only works on ABS inner parts. My race hood and parts from glass tech have aluminum molded in them to make them ridged . Good fiberglass parts all have aluminum molded into them at those areas. You can also put a strip across the back to make it straight from looking over it in the car