A good boat repair facility (boat yard) would be a good place to start. Boats are often made of
fiberglass and have a gel coat finish. Some cars and many "big rig" trucks have fiberglass components, so check around for body shops too. A body shop that works on Chevy Corvettes might be able to help.
Often the boat yard guys are independent contractors or one man shops that travel from shop to shop. The boat building business in western Washington is pretty much gone, but there are some former employees that still have the skills if you can find one. Best of success.