Definitely an arsenal or period (1920s probably) workshop conversion of a LP08 holster. I can not help with the top marking but the middle one is to the 10th field artillery regiment. You can look that unit up and find out the Division and corp it was assigned to and the campaigns. In 1916 the artillery was still receiving these LP08s but by the end of that year and for the rest of the war not so much. Most all of the 1917-18 production went to arm the infantry assault companies.