My coach was built in 1973. If the fuel lines have not ALL been replaced, plan on doing that job now. From the tank top to the carburetor all the existing rubber lines, between just plain age and alcohol, are probably shot.
Recently I replaced all the fuel lines with either Polyarmour or SAE J30 R14. The work was worth the piece of mind.
A lifelong waterman and his bride going dry places for as long as the fuel money lasts.