coin of athens attic owl 566bc on one side only?

Answer 1

I'm sure there will be reference to Greek coins on the British Museum's website. I also think that if your coin says '566bc' on it that it's a toy piece.

Answer 2

It is a reproduction. All of the ancient Greek coins from that period have Athena on the obverse and her owl on the reverse. True one side or the other may be off the planchet some, even a lot but some of the die does show.