[bobcowan]

Anodizing hardens the surface and dye's it. The color becomes part of the alum. It's not a coating like paint. Stripping it off means removing material.

Anodized alum can still be stained by gas and some oils. Not nearly as much as raw alum, but it can still be stained.

You could probably get much of the shine back by having it powdercoated in high gloss. It will get most of the shine back, thouroughly seal the surface, and retain the color you want. Plus, it can be done in a few hours for just a few dollars (compared to re-polishing).