My 2003 Sunova 30B has de-lam on both lower sides. This winter (if I have time) I'm going to cut the bottom 2 feet of fiberglass off and remove the rotted wood. Then I'm going to spray foam insulation on it and cut that flat. After that's done, I'm going to cover the lower sides with diamond plate glued and riveted to the aluminum sidewall structure then paint to match. I'm also resealing EVERYTHING including all windows.
I think it's worth the effort. I've only got 20K miles on it and we looked at a new one. They wanted 90K for anything we'd be interested in and we'd have to upgrade the new one after purchase to get what we have now. Doing the work myself, I estimate costs at around a grand but even if I put a couple of thousand in this repair, I'll still come out way ahead. Diamond plate can be purchased on-line in 4x8 sheets.
The dealer offered 11K in trade. That was an insult. I know I could get 25K or better easily for it on Craigslist. They just wanted to steal it. I don't go back in there anymore. If they had offered a fair price we may have traded. Dealers suck!
NOTE: Above plan may change without notice. LOL