It will be a whole lot of work to rebuild, though you presumably already know that. For most people, I think the best advice would be to walk away; but if you're looking for a large project to work on, maybe it would be reasonable. I doubt you'd make much money off the venture in either case, especially once you factor in what your labor is worth; a 20+ year old class C, even if it's in pristine condition (which of course this one isn't), is not especially valuable. Likewise 20 year old RV appliances do not command particularly high prices.
Water damage, as you probably already know, is quite often more extensive than it first appears.