RWTF, according to Semmer's book, 138129 would be from 1910, last year of production. But these records are really based on shipping, not production, and as they closed out the line, 1910 was a big year for shipping. The number range was from just a few guns under 138000 to just a few under 141200. So it's likely yours shipped early in the year.
Thanks, my Canuck friend- Do you know what the LAEY stamping on each underbarrel signify? Also, on the bottom of thre barrel ;lug-- at front is the upper case letter "P"-- at the rear section is 51 over XX- que pasa???
