By the time you buy all of the items to do a really nice job, you can probably pay a pro to do it for you.. NOT some high priced shop, but a polish guy that works out of his home..

You can start with the cotton wadding cleaner, Neverdull.. If its not cleaning them, go to sand paper or steel wool with an aluminum cleaner type of polish..
Finish with a mothers or autosol type of polish...

There were two types of finish's offered on Ansen type slot wheels in the day, polished and a "turned" finish... I am sure you can polish out the "turned" finish if you want to...

Personally I would never clear coat em..

I did see a few years ago some sort of sealer ( Zoop) you apply to aluminum after you are done polishing them.. It claimed to "seal" the aluminum pores so the shine would last longer... Never have used it...

I had the wheels polished by a pro ( truck in pic) in the early 90's.. They were really sad before I had them polished and looked unbelievable when done... NEVER had to redo them in the 10 years I had that stepside truck...

First two pics are before, second two are after...