Originally Posted by RVGuyRaleigh
They did not change the type of Aluminum used until about 1981, so anything prior to that should have the same Aluminum and look great. I have a 1975, just had it stripped, sanded and repolished and it's absolutely the nicest thing I have ever seen.
We're talking about two different things here...
1) In 50's/60's there was no mill finish texture, it was smooth so there is no need to sand or use other techniques to get through the texture
before polishing, as you (and other polished 70's trailer owners) did.
2) In the 80's the alloy changed which is a different aluminum composition
- this has nothing to do with the mill finish texture.
Regardless, even 80's or newer trailers can
be polished (all metal can) - it's just the aluminum alloy is different so the shine may not be quite as bright or last as long.