Welcome! There are legions of Flying Cloud owners here... having had a couple of '53 FCs in my yard last summer, I can tell you that everything in them (except the 12v
wiring) is bonehead simple and (relatively) easy to get to and repair or replace. They were built during a much simpler time using mostly apartment-sized appliances and standard plumbing fixtures.
There weren't any manuals for Airstreams until the early '70s.
Good luck, and be sure to post lots of photos!
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"