WOW! I guess I'm going to have to change my "Only Airstreamer in Edgewater" tag! Welcome aboard!
There are almost as many ways to polish an Airstream as there are polished Airstreams out there. Generally speaking though for a 70's trailer, the first thing is to strip the clearcoat. If it's still pretty much intact, this may be all you want to do. If it has failed over the years and the aluminum beneath is splotchy w/oxidation, you will need to polish it to get rid of the unevenness - although there are some who are trying to achieve a "matte" finish with various levels of success.
Search the polishing forums
and specifically this thread
for what we have done.
Good luck in whatever you decide to do...if you want to meet up sometime, PM and we can arrange something.