Originally Posted by Jon in AZ
The biggest thing is whether you still have the support ledge under the front window, and if so, whether it is still sound.
I replaced my ledge with African Paduck resin wood. It is so heavy it will not float (or absorb water). I removed the insulation under the window (that was already loose from the moisture). Next I scuffed the fiberglass with #80 grit paper with a disc grinder (DONT! go too deep as the glass is less than 1/8" total thickness. Make a cardboard template that exactly matches the curvature of the under window location of the new wood. Use epoxy resin and hardener to glue the wood to the camper. Reinforce the underside of the wood with two or three layers of fiberglass and activated resin. Sand the wood and glass reinforcement. Coat with clear resin, trim and re-glue the insulation. I think the result will make you proud.
If you have any doubts there are many videos of working with fiberglass. Just don't forget to wear safety equipment, Glasses, Dust mask, protect your hands with latex gloves. I did not have any upper bunk and did not like the idea of loose poles so I built a hinged upper bunk with built in legs. Take a look at some of the photos posted here.
I have several projects on there including a plywood template of the hinge I made for the upper bunk shelf. Also a couple of photos of the upper bunk shelf. BTW the air conditioner did not work well and was taken out in favor of drawers that I will build this summer if I get time.