CC&R dated 1973 says no RVs, trailers, boats can be stored

Time to look elsewhere, but if you are really stuck on that place, since they have allowed others to park offending vehicles, you would have an argument that they are selectively enforcing the rules.... that being the case they would have to either go after all the others, or let you slide. Either way, it'll be a pain for you and the rest of the people.