Fender brace question

[raphyel]

I have two front fenders. They are in great shape, but the brace is shot. The previous owner used fiberglass to reinforce them and they seem to have held up, but the glass if starting to peel away because of underlying rust. Also, the screw hole that is in the bottom was covered with glass and drilled out. There is not bolt welded inside, so they cut a slot in the glass to allow someone to put a bolt on.....Finally shoule I replace them of just cover them with undercoating..I dont plan to usethe truck as a daily driver. Just looking for opinions. also, has anyone changed the brace on a fender without putting a patch on?