Be careful with paint stripper, I once did that and aluminum turned matte gray, and I mean dark gray.
It is best to use something like 400 grit wet-sand sandpaper, than 600, and than for even finish I use Cameo copper cleaner, or Comet scrubbing powder on a wet rug. And just buff it as best I can. After that I use chrome polish either on a towel and buff the part for a couple of minutes, or use a buffing wheel with chrome polish in the drill. That brings out the mirror finish. You can get most polishing pasted at any auto stores. After a while it gets addictive, whenever I see unpolished aluminum, I have to make it shiny.
And don't forget to wear a dust mask!