Restored Coins

There are a couple different usages of the word but the most common would be in regards to nickels, usually Buffaloes. A restored date nickel is one that has been chemically etched to bring out more detail. This method can give dateless Buffaloes a purpose again, etching mintmarked coins can occasionally produce a semi-key or key date coin. The less common usage is usually only seen on very rare damaged coins, it involves metalworking and engraving skills such as those practiced by Allen Stockton.

Aha! Interesting Link! that was a big surprise for me

Thanks biokemist!

that's also done here for the 1903-1912 peso varieties of 90% silver coins salvaged from the sea, pitted and all black tarred. But the semantics here, the word used is "cleaned" or "cleaned + toned" so the word "restored" didn't ring a bell, until now.

thanks again!