I got ahold of some US-made repro 428 CJ "Snake" Cast valve covers for my Mach 1. My goal this weekend is to polish them to a mirror finish to match everything else in the engine bay. I like the "polished" look far better than chrome. My experience with polishing aluminum is that it looks great until you breathe near it, then it scratches. This leaves me with three choices: 1) I was advised to look into a ceramic coating like you'd apply to paint. Any experience with this? Sounds like a good option but the substrate is still soft as butter. 2) Anodizing. I've had tens of thousands of parts anodized over the years in my line of work- clear, dyed, hard, you name it. It always comes back dull even with pre-electropolishing. Still, some people swear that certain ano shops can pull off a clear ano that doesn't dull the surface. I have yet to see it. 3) Automotive clear coat. I've tried this before too, and it always yellows in the engine bay (Especially high-temp). Is there one I should be looking at? Any recommendations are appreciated.