A coin with an intriguing perforation, known to us with such only from this one piece.
It is possible that the perforation is unrelated to the circulation or production process, but made accidentally - on the principle of trying to die-cut with a cross, for example, by an engraver or jeweler.
Intriguing item. Perforation made on a virtually uncirculated piece of the coin, only with later dirt or tarnish.