newbie trying to date a 1917 DWM

[fuzidave]

ok. maybe chalk this up to being a total noob. here's what i see...

on the front is 751. i see 51 stamped here and there.

now on the barrel, on the right side i see the stamp.
on the top i see 1917.
on the left i see 751.
and on the bottom of the barrel, i see 3826m.

it's that 4 digit number that throws me.