Rifle is a matching '91 Loewe Gew88. Cancelled unit mark on rear band is B.K.24.xxx. I'm usually OK with interpreting these, but both have me stumped. Landwehr pioneer, but the OP do not have a period between them? Any help great appreciated.
Probably Landsturm (Infantry Battalion) Opeln, 1. Komp., Waffe Nr. 80.
B.K. etc. probably Bezirks Kommando 24; sometimes followed by a placename abbreviated in upper case.