Ok - First off DON'T try this at home . I an not a professional. I run these test under the cloak of darkness. This was just a tot lot find and thought I would see what I could with common household chemicals. 1st 2 is the way I found it. ClS did not put a dent in the crud. 2nd 2 our a soaking over nite in Lime Away. Now I have a person that wants to buy it because he thinks it was a mint error struck on copper. (Just fooling every on) Have a great day
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