Follow-Up:
Sounds to me like your problem wasn't the Rialta in general, but the crooked RV dealership where you bought it. How did you end up buying a motorhome with a cracked head? Surely you took it somewhere to be mechanically inspected before you bought it. If nothing else, if you couldn't find anyone to inspect it in your local area, that should've told you not to buy it because you'd have difficulty in getting it maintained. It sounds like common sense failed you, as these are steps you should take when buying any used vehicle, especially from "Papa's Camper", if that was their real name (?!)