Did some name plates recently, you can see them here:
https://community.carbide3d.com/t/executive-name-plate-x3/25887
polished the aluminum with wet/dry 300, 500, 600, 800, 1000, 1500 and finally 2000. Wanted to keep that beautiful shine so I sprayed with Dupli-Color Wheel Gloss Clear Coat, which is holding up very well!
But I think the smooth faces on my project were probably easier to poilish.