An intriguing and very rare item.
Originally described by us as a variety with a full date, without mint marks (R3), but under the monogram something like a single B is shaped (which would give an undescribed Kopicki variety with a single letter, instead of a BB under the S, but according to us this is a punching out of the stamp).
In addition, it is distinguished by the date type itself - where the six instead of being stamped with a punch 6 is a zero with an additional tail (in our opinion made from a punch I).
Mint Bydgoszcz - based on the location of the letter.