When I polish a set I start with wet/dry sandpaper of 240 grit to smooth out the really rough areas and move to 400 and finally 1000 or so if necessary. I then use 8" sisal buffs on my bench grinder with the shields removed and simply buff to a high luster. Sometimes you find spots you need to hit with sandpaper again. I usually experiment with the different buffing compounds to find the one that give me the best cut. I cannot remember exactly which ones I use. I also keep a soft loose wound buff for finish polishing.
The biggest problem you will have is maintaining the luster once polished. Most clear coat paints are unacceptable and will dull the finish so much that it will look aweful. The best solution I have found is Nyalac Clear from Eastwood. It goes on in a real thin coat and does not cut the luster too much. The only downside is that gasoline will remove the finish immediately. I usually just pull the valve covers when this happens (or every so often) and strip all the clear with mineral spirits, buff real quick (minutes), and then reclear.
I have not messed with buffed aluminum pieces in quite a while so there may be some better products available to both polish and clear, this is the way I do it though.
