Having had an '85 325 moho and having looked at a number of the Airstream fiberglass sided mohos over the years, it is my guess that a couple of things happened. First the aluminum silver bullet style moho was very expensive to produce, and other mohos in that price range became high-end diesel pushers while the Airstream remained on the P30 gas chassis. Second, Thor already had a number of mohos in production, so it was no great trick to slap Airstream stickers on a current production product, and sell it at a competitive price. There's nothing wrong with the fiberglass LandYachts per se, but there's nothing special about them when compared with other offerings from other companies of the era. They're just not the aluminum mohos.
AIR 2053 Current: 2004 Airstream Interstate "B-Van" T1N Sprinter & 2006 Born Free 32 RQ Kodiak Chassis
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"