Here's a tip that I ran across on the 'net:
To polish corrosion off of chrome or natural aluminum parts, get some sort of metal polish compound - the stuff I've been using is about the consistency of automobile liquid wax - but use crumpled aluminum foil as your polishing "rag". I'm fixing up an old 10-speed that has the bottom half of the forks chromed. I tried the polishing stuff with just a rag, and with a buffing wheel on a Dremel, and was not getting good results at all. Just for the heck of it I tried the aluminum foil, and the forks look like new! A coat of auto paste wax, and so far they still look good.