That inspectors marking shows on Brit, Canadianand Private Purchase S&W revolvers. The last 2nd model Hand Ejectors up to 71,000+ range (1917) exhibit it.
I believe that it was probably the accepting officer based at Remington.
Early 2nd models will often have DCP Canadian Inspector markings - on Brit guns - supposedly early in the war the Canadian inspectors were authorized to inspect Brit contract arms.
That is why Remington and Winchest .44-40 rifles have Canadian DCP proof markings.