74969 is MC/Cpl L J William, later Acting Sgt.
74963 was either not allocated or did not serve overseas so no medal record.
Of those you listed, 58, 64, 65, 66, 68, and 69 went overseas on the same date 31 July 1915 as William Keeling.
Of those, although medal records exist, only one 74969 has any other records which identify a unit to be found. In 1918 he was in 7th Signal Company in the 7th Division.
Another quirk of the system is that 74958 was also issued to a William Edward Slater who was a Sapper in a unit in Salonika in 1916. The Royal Engineers were not alone in having duplicate numbers.
So far no sign of Mason except on a medal roll. He incidentally went to France in January 1915 so had been there 6 months when your grandfather arrived.
MaxD
