I have a confederate half dollar which is toned and dirty, typical of the average-circulated seated liberty half. It does not have the word "copy" on it. I believe it may be an electrotype copy made in 1961 as a Civil War Centennial souvenir. Do such pieces exist? Is there an internet article explaining how an electrotype copy of a coin is made? Some parts of the obverse are flattened -- is there a remote chance that my coin is a Scott re-strike that accidentally got into circulation?