Mothers Billet Metal Polish
I read yesterday a post by a metallurgist in the Astromech forum. He said the best way to polish billet is to avoid sanding and removing material, just use some Mothers Billet Metal Polish. You put a small amount on a terry cloth and just rub on the dome until a black residue appears. Wait about a minute and then wipe the residue clean with a fresh terry cloth. I was skeptical, and the billet polish is not cheap, but I’m a believer now. Below is a photo of the dome after polishing the left side for less than 2 minutes. I used about a quarter size dab of polish.