10 Zlotys Karol Świerczewski, Trial Strike

Świerczewski — a Red Army general who spent much of his career fighting other people's wars, from the Spanish Civil War (as "General Walter") to the Oder-Neisse frontier — was assassinated by UPA fighters in the Bieszczady mountains in March 1947, an event the Polish communist government immediately weaponized into martyrdom mythology. This trial strike predates the circulation issue, produced at Mennica Polska as part of the approval process before the design was authorized for general coinage.

The Fischer and ParM references distinguish this as the "b" variant within the proof series, suggesting at least two trial configurations were submitted.