There is no 14/1 stamped on the gun. Both barrel flats have 14 stamped on them. The 4 is very faint on the left flat but is there never-the-less. Amazingly faint marks such as this quite often show up better in a picture than looking at the part directly. Look carefully at the picture & the 4 is visible.
Prior to 1887 only whole gauge numbers were marked. In 1887 the in-between gauges began to be used. Also, the Chamber mark 12 C in a diamond as Toby said was introduced in 1887, so this means this gun was not built prior to that.
Had the bore at original proof been large enough to take a .701" plug gage it would have been marked 14/1.
So as Toby said it was made from 1887-1904 & the barrels were originally proofed as 14 gauge with 12 gauge chambers. If memory serves me correctly I believe the word Choke also replaced the Not For Ball mark in 1887 as well. Yes, it originally had choke in the left barrel with the right barrel a cylinder bore.
I have a Birmingham proofed W Richards built prior to 1887 which was proofed as a 14 but has 12 gauge chambers. This one did not have the chamber mark so it cannot really be proved if the 12 gauge chambers are original or not. Both barrels on it are cylinder & they currently measure just shy of 13 gauge.
