What the Heck is this thing?

[alvin]

Curiously, is this 9m/m? Many of them were rebored to 9m/m probably because original bore was bad enough. Understandably, who would clean up the bore everyday in the past.... I saw many of these coming with new 9m/m bore. Most rebored fine, but a few that I met have the hole not in the middle of the barrel.