I have a cracked fiberglass roof on my 2005 Allegro Bus from a baseball sized hail storm. I've been looking at roof options and I've seen two ads for vinyl layered roofs. There are two companies who...
You might try a boat repair shop. They would know how to fix the roof. Or, a good handyman could handle this type of repair. Be sure he drills a small hole at the end of the crack to stop the spread. Then pick up a fiberglass kit from Walmart, spread the resin, add fiberglass cloth, spread more resin, and a little more cloth. After it's cured, spray with Krylon. I've done many fiberglass repairs and it's pretty easy. Good luck and good travels.