Regarding polishing; I suggest taking a page from the car buffs (pun intended.)look up "zoops". The were located in I believe Beaumont or Banning in Southern California, Riverside County. The have a polishing preservation material. I need to polish the Aluminum valve covers for my 1957 Thunderbird car. I will be using the Zoop's method and materials. The underhood area of a car is very hostile, because of temperature changes and the high temperatures involved, to anything under the hood. Anodizing when worn looks liked a bad clearcoat/basecoat paint. A complete polishing off of the old anodizing needs to be done to polish to a jewel like finish. Then use Zoop's or re-anodize. If you look up anodizing, it is not a higly difficult process to do at home. In fact one can obtain dyes to "re-gold" those Simplex and Mafac gold brakes and derailleurs as well as shifters or headsets. Black can also be used to refurb a "Vent Noir."Happy Trails,John Strizek,
Sacramento California, USA, planet Earth