Greetings Neil!
The part is not unique to Airstreams, but it is not as common as the
Valterra that is used by much of the Industry. What you want is a
Thetford connector. If your WalMart is like the one near me, you won't
find Thetford connectors there, but most any RV dealership with a good
parts department should either have the Thetford connectors or be able
to order one for you. I know that they are available several places on
the web - - Inland RV or Ace Fogdall RV to name two possibilities.
Good luck with your Coach!
Kevin D. Allen
1964 Overlander International/1999 GMC K2500 Suburban (7400 VORTEC/4.10
Differentials)
1978 Argosy Minuet
1975 Cadillac Convertible (8.2 Liter V8/2.70 Final Drive)
WBCCI/VAC/Free Wheelers #6359