Welcome to FiberglassRV.com. You've found a great source for advice about fiberglass repair. (There are probably topics in the Problem Solving
forums - maybe even some in the "Care and Feeding" forum... and of course, you can ask your own questions.)
FWIW, we usually put threads about RVs that are outside the focus of the site (molded glass travel trailers) in our General Chat section, but if your renovation is all about the box and not about the engine, drive train, etc., it might be appropriate for our Modifications forum. (Not sure.)
Either way, we're glad you're here!