If you are going to do it for gratis, I have 3 that you can plate for free. Thanks in advance!
Mothers or Semichrome Polish. Lots of elbow grease and a boatload of rags will do wonders."Product is known to the State of Florida to cause severe swelling and itching of rectal area. Product may result in death, blindness, or hairy palms if applied to groin. Do not use as douche without first diluting with lukewarm water by 50%. Use of Aluminum Jelly for PBJ sandwiches is not recommended for children under the age of 12."
Get some Mother's Aluminum Polish and a rag. You'll love the results. "Collinite Metal Wax" is another terrific aluminum cleaner, but it's hard to find unless you have a well stocked boatyard store around.