SDH: Yes, the grip retention screw comes up from the bottom. The second (original) barrel is Smith & Wesson.

I will add photos of another pistol, this one marked "A O Niedner, Malden, Mass", It is serial 1610. The barrel has a liner and there is a trigger stop. The remainder of the pistol looks factory.

I'm not sure what the 688 in Set Trigger's numbers imply. The 4428 is apparently the Smith & Wesson serial number. Pope barrel number 681 is dated 6/18/26, so with a target from 1913, 688 could not be the Pope serial. 603 is dated 12/20/22, so Pope's production was very low by the 1920s!