Me thinks montenegrin to once again to be spot on that the numeric string isn't proofhouse data but bore and caliber. I starred at the "29.11.6" for some time and couldn't discern just why the "." were midway between or above the numbers. So the longarm's assembly date range is post 1891 and possibly pre-1899. Knowing the diameter of the scattergun tube would be a plus.

Kind Regards,

Raimey
rse