a few years after we bought our new Itasca Suncruiser (and AFTER it was out of warranty) our dealer discovered that there were many spots on the exterior where the fiberglass was 'popping'...small pencil eraser sized areas. they contacted Winnebago who agreed to replace the entire fiberglass exterior for us...nose to tail, both sides...at zero cost to us. all we had to do was remove everything from the interior, deliver it to and pick it up from forest city.
the point is that the exterior fiberglass *can* be replaced by Winnebago but I have no idea what it would cost. won't be cheap.
good luck.