Hope this link works. This is a pretty well preserved Belgian 8 gauge market gun. Metal and wood generally VG. Bores are Good+ with pinprick pits throughout. Tight rib.
https://imgur.com/a/zVFcizp

22.6 mm huh? That might be a Maker's Mark near the encircled >>ELG<<. I can't quite make it out.

Serbus,

Raimey
rse

22.6 is bore in millimeters. A 6 bore is 24.0 according to a guy with an almost identical gun as mine.