Well, I use 2 different buffing wheels with 2 different polishing compounds: the first will easily remove oxidation; the second adds a smoother polish, though many times I omit using it because it makes parts too shiny for my tastes. Gouges and deep scratches you want to sand out before you start, but oxidation is just a surface effect on aluminum.

You can polish the anodizing off with a buffing wheel, though it takes quite a bit of work.

The Campagnolo Tipo and Record/Nuovo Record hubs were never anodized. I don't think Normandys or Zeus are either, nor the Gnutti I recently built. Don't know about the Japanese stuff.