Blackdog & Fal308:
I have checked the same book as Fal308, and have identified the same piece that he has identified. I cannot find where it was made in or during 1915. Additionally, the 5 pt. star, is stamped in the grip, as a Pieper trade mark.
I have also noticed a similar star stamped on the left side of a Nagant gas seal Revolvers. Unfortunatley, I am unable to locate exactly what you have.