Feel Like Warrior Swejk - Austro-Hungarian Seal/Piston of the 91st Infantry Regiment

An Austro-Hungarian Army stamp piston from World War I, mounted on a cardboard backing with a handwritten description explaining its historical and literary significance. The stamp belonged to the K.u.K. Infanterieregiment Nr. 91 (Imperial and Royal 91st Infantry Regiment), specifically to the field company command (Feldkompagniekommando), as evidenced by the clear inscription in the rim and the centrally placed double-headed Habsburg eagle. The artifact has a special cultural dimension, as it was in this authentic unit that Jaroslav Hašek and his most famous literary hero, Josef Schwejk, served.
Diameter: 3.5cm.
Overall condition as shown in the photos.