2024t3 is what I have used to repair / rebuild a number of airstreams from - https://www.airpartsinc.com/shopdisplayproducts.asp?id=28&cat=Aluminum+Sheet+%26+Coil.
The lower skins on my 4106, some PO took a disc sander to in areas and there is no way to re ano. it
my plan is to sand smooth and polish.
I have about 400hrs of aluminum polishing experience so i know what i am in for.
I polished a test spot on the bus and left it outside for a few months and so far so good.
I was just curious the purity of the alloy used in the 4106.
I sure wish the endcaps were aluminum on the 4106... but that is what gloss black is for i guess
I polish my 2024t3 airstream - about 5 hours - once a year and am very happy with it.