Your vintage Airstream is made with expensive, durable Alclad aluminum. It will likely polish up very nicely. There are many treads on this stripping and polishing process. It will cost about $500 ($100 for compounder, $250 for a Cyclo, $200 for polishes and buffer pads) and take you about 400 hours of hard work. Sounds fun, don't it? I did my 34 footer so I speak with some experience.
The Nuvite website has a good tutortial on the process. So does Vintage Trailer Supply.
You will make your old Airstream look significantly better while you give yourself significantly more work every year.
By the way, polishing the exterior is not the first order of business. Frame rust, floor rot, axles, brakes, tires, plumbing, propane, electrical, and reducing weather leaks are more important maintenance items on an old Airstream. Don't be guilty of putting lipstick on a pig. Make sure your hard earned dollars and time go to stabilizing the major systems first.