I am interested in about learning Leica Tread Mount or FED 1 Body Finish technology. I think acid could be used to finish the bare aluminum in to warm touch pored finish. I want to finish my aluminum - not marine grade - parts to same finish.
Or was material brass and electroplated with a chemical ? Or is it chrome or nickel finish ? I am talking about top part which portholes etc. belongs .

Umut