Post some pictures, water damage and delamination are a a tough thing to overcome. How far did it spread. If you had a covered place to work on it and like difficult projects this sounds like one. If you have to store it outside in the elements you cannot get ahead of the damage that is going on.You will never recoup what you are about to spend on this motorhome. But that being said with it being free ,if that motorhome was in good shape ,no leaks or water damage you would be 10-12,000 dollars ahead.As is you have squat. MHO. Hey I have done harder projects to me Labor is free if you do it all yourself. I have a 97 p 30 myself it is always a work in progress.