just got done restoring finish on my 88 winnebago superchief.
i used a product called polyglow to refinish fiberglass.
it did an unbelievable job bringing back color and sheen.
easy application. i had seen it on an older model winnie and thought i would try it. cost about 55.00 plus shipping well worth it.
There are many RV salvage/specialty parts sellers out there, you just have to find them. I recall that someone took an enormous amount of time to list all the sellers phone #'s and addresses and posted them in response to an inquiry. Try doing a search on the board. The only one I can recall is Colaw and they have a website.