Travel Trailer Value After Rehab

Hello everyone. Not sure if this is the right thread, so please feel free to move the post if not. I bought a 1994 Chateau travel trailer a couple years ago from a friend who told me the back corner needed work. He said there was a little rot. Well I finally started looking into it and there's a lot of rot. One corner of the roof/ceiling, the corner stud, most of the floor. I was going to just fix it and sell it, but every time I remove another part, there's more rot. I'm considering gutting the whole thing and rebuilding it with new materials. I wanted to use that synthetic wood stuff, foam panel insulation, and anything else I can find that's waterproof. Basically making it so it will never be able to rot again.

So I have a few questions. If I rebuild the structure (including the floor) with all waterproof materials, would it increase the value as opposed to repairing it with just wood and fiberglass insulation? What is a reasonable sales price if it's repaired like this? Basically I'm trying to figure out if it will be worth the effort and materials cost, or if it's a wash and I should just sell it for parts or something. Thanks in advance for any help.