C1 - 2x4 Air Cleaner Finish

[Brad K.]

Any hints on improving the finish on the very shiney aluminum repo air cleaners. The '59 TIM specifies a "lightly" polished surface (I assume that is as opposed to a "brightly" polished surface). I think this means a "matt" finish instead of a "gloss" finish. I need a technique:....Things like tools, chemicals, length of time of contact with the chemicals, etc.

Thanks in advance,
Brad