Boguslaw Ryszard Wolniak a.k.a. Boleslaw Wnuk, a.k.a. "Mint", "Powoli" (born March 9, 1907 in Warsaw, died March 31, 1986 in Gliwice) - a communications major in the Polish Army, cichociemny. He was a commander of a training company and an instructor at a communications training center, as well as head of the radio center at Base No. 10 in Ostuni (Italy). He took part in the Warsaw Uprising. You can read more about him here.
A guttergraph with the engraving:"To remember our common effort in the workshop / From Sgt. Maj. / Wolniak / Polish Forces / 24.IX.1924".
Dimensions: 13 x 12 cm.