The original story as I heard it was that the present owner that is selling the RV built a new fiberglass roof. I had/have no idea what the original roof was made of nor do I know why it was replaced. I am getting this info from a friend of mine that is the prospective buyer.
Since the roof was rebuilt, the only way to find out why, is to contact the original owner.
My next question was how significant or worrysome would someone be buying it with 105,000 miles on a gas engine? The engine was supposedly well maintained.