I have this nice set of Sugino 165mm aluminum 110BCD cranks with quite a bit of oxidization/pitting. After cleaning the left crank arm and polishing with a few rounds of Mother's Aluminum Polish, it still has pitting/oxidation. I'm wondering if these cranks are anodized and need to be stripped with yellow Easy-Off first? How do I tell? I've also tried sanding with 1000 grit sandpaper and all it seems to do is dull the surface rather quickly. I imagine if I kept at it the pits would disappear though. I didn't try very hard.

It's difficult to tell, but in the photos only the left arm has been polished. I have done virtually nothing to do the right arm. Any tips? Thanks.