Welcome HD, the lever boss code dating system didn't start until 1949, 49=A, 50=B, etc. No O or Q, they look too much alike. The number on your boss is an inspectors stamp. With the rounded fore arm, with the line cut around the tip, makes it a pre war model R. Others will be along with more specifics.

Last edited by JoeMartin; 04/28/19.
I'm not greedy, I just want one of each.

Remember Ira Hayes

JoeMartin