aluminum polishing is very easy to do, I'm polishing my case right now, and will be polishing my empi 5 spokes as soon as I'm done.
first thing to do is use a motorised dremmel with medium sandpaper to clean up any casting lines, in the case of the brake drums you shouldn't have to do this.
next go to it with 320 grit sandpaper, getting everything smoothed nicely
then take a high speed drill and polishing wheel. using aluminum polishing compound go to it untill its perfect.
there may be some deeper scraches left over that you missed with the 320 first time around, do those spots again with 320 and polish again.
I've actually found that for larger surfaces (ie no small details) that denim tends to polish very nicely, cut between 6-8 circles of denim (old pants work good) about 6" in diameter poke a hole in the center of each. slip a small bolt through the holes of the circles, with a washer on each side, tighten a nut on the backside and tighten in the check of your drill. Makes quite a mess from the lint as the denim wears down, but it polishes nicely, and can even be used to get inbetween the cooling fins on the bottom of a case.
VB
[This message has been edited by ViolentBlue (edited 02-20-2000).]