Old drum:
The problem is that the outer part of these is slightly porous and really absorbs brake dust and general schmutz from the atmosphere, then gets cooked for decades. I'm imagining that most detail shops would not know how to get these looking new again. Hell, I couldn't figure it out until I remembered the same challenge on my 911SC case when I rebuilt that engine in '02. At the time, I figured out a method that left the experts scratching their heads wondering HTF I got my porous alloy cases cleaner than they were when they were made.
Anyhow, Voila!
Another before shot, just for emphasis. I could tell you guys how I did this but I'd have to kill you all afterwards and that's a lot of traveling.
