Looking for some info on the proof marks on this old F.W Kessler 16 Ga hammer gun.

Wondering about the "Nitro" proof on both sides of the barrel? I thought "N" was the mark for nitro proof, it is also outside the barrel flats.

Is it possible to determine the year of manufacture.







Any help will be appreciated.

Thanks


Last edited by Oberndorf; 07/04/15 05:38 PM.