Congrats on your new camper! There are not a lot of these out there, I wonder if anyone has an idea on what the total production # was?
Here's the ebay link for the "Dexstar" style wheel, same as I have on my 72 FG-16: 14 x 5 5 Dexstar 4 Bolt camper Trailer Wheel Rim for St 205 75R14 Tire Dexter | eBay
What does your gelcoat look like, when you say it's worn off do you mean you see fiberglass strands from the outside?
More than likely it's just filthy dirty and chaulky from sun fading. Try cleaning it with some of the spray cleaners first that are made for boats/RVs. I just did this to mine & then used an automotive style buffer w/a wool pad and buffing compound. I didn't realize the gelcoat color was an off white almond until I buffed it out!
.......and of course pictures when you get the time!