Greetings from the other side of the pond. We have several members here from the UK and Europe. They tell us many stories of the strange looks they get pulling the Airstreams around over there.
Try Airstream Corp website.
www.Airstream.com Somebody posted not too long ago that they were selling older editions of the owner's manauls and shop manuals these days. If they are of no help, do a search on this site for a company called Secretarial Services. That's where many of us have purchased ours. Be prepared to shell out a couple of bucks, however. I think I paid about $85 for the shop manual. The owners manual was about $45. I am a bit dissatisfied with my copy, too. It is essentialy just a photocopy and the quality is a bit poor (especially for the money).
Good luck with it, let us know how it works out for you.
JIm