Those scales are really nice and your polish is a wonder!
Some scales and scale liners in history were made of and still are of "German Silver," Nickle Silver," and other forms of white brass. Or aluminum. Not a really great problem.
A brass / copper scale heated to make a gun metal blue rainbow is a thing of beauty. It may be sealed with a baking lacquer or enamel that is set in the oven at boiling water heat. Practice on a scrap first!
~Richard