Otto Bock was some kind of sporting-good supplier based in Berlin during the late 19th & early 20th century. This double-barrel shotgun for sale on Gunsinternationl.com bears his name, even though I’m pretty sure he didn’t actually make it himself. Whatever the gun’s story is, it’s a hell of a nice side by side in awesome original condition.
A lot of the gun looks British. To see what I mean, compare the action, lockplates and fences to this and this pic of an A.A. Brown. It does have some stout Teutonic overtones like the horn inlaid drop points, the broad trigger blades, and the muscular bead work and scultping ahead of the squat toplever.