Some times they show up in the classified here or on Ebay. You can buy some later model service manuals directly at Airstream.com. The vintage airstream club VAC (interclub of WBCCI) also has some tech information on line. For a particular problem search function here is pretty helpful.
For the moment, the earliest one that Airstream sells in their online store is for 1972. Much of the information in the 1972 manual would apply, and they still offered a 21' Globetrotter for '72, so that manual might be helpful if you can't find a 1970. I use a '75 Airstream service manual for my '75 Argosy, it has enough information to give me the right ideas, but there are small differences most of the time.
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— David
Zero Gravitas — 2017 Flying Cloud 26U | WBCCI# 15566
He has all of the virtues I dislike and none of the vices I admire. — Sir Winston Churchill
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