I'm in the same boat.  Picked up the bike for a steal, but the aluminum cases are all pitted to death (not to mention the rusty spokes!).  :'(

I've done a bit of aluminum polishing by hand in the past, and planned to attempt to polish up the parts on this bike (last winter, never got to it).

The technique I learned is this:  After removing the clear, use stages of wet sanding.  1000, 1500, 2000 til it's good and smooth.  Then I buff the parts with a polishing wheel and rouge on a power drill (I bought a cheap $20 Ryobi since I hated putting pressure on the bearings in my DeWalt).  Once it's super smooth, then hit it with some Mothers or equivalent aluminum polish.  It will look like chrome/mirror finish, but it's a lot of elbow grease!

Of course there are power buffers/polishers available, but this is strictly DIY on the cheap.

Ultimately, the raw aluminum will need to be protected, using something like Zoops Seal or equivalent, or maintained with polish regularly.  

After trying several ideas I settled on parachute cord w/ the middle strings pulled out. A full wrap on a spoke with some polish of sorts & pulled tight, sliding it back & forth it climbs up & down the spoke,, quickest approach Ive come up with. Still hard!