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re #1: Yes, it sounds like a 15 kopek coin.
http://www3.tky.3web.ne.jp/~jafarr/USSR.htm
A friend who was born in the Soviet Union told me an interesting story
about the 15 kopek coin, which I've found a version of here:
http://www.wired.com/wired/archive/1.04/russnet_pr.html
Apparently all the payphones in Russia at one time were built to accept
15 kopek coins, but when the Soviet Union dissolved and the Russian govt
stopped controlling the economy, kopek-denominated coins were worth so
little they stopped minting them. However -- they still have millions
of pay phones throughout the country that are built to only work on the
old 15 kopek coins. Consequently, such coins trade at many times their
face value because they've essentially stopped being used as a currency
unit and have switched to mainly being traded as a phone token.
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