M1903 Springfield Cartouche markings

[gunnyarlow]

I own a M1903 Springfield rifle - BBL - 1931 and a SA/SPG cartouche with a "RI" (Rock Island Arsenal) marking on the fore stock. I have seen M1 Garand markings also with the SPG markings - I have asked in other forums for this information but have received conflicting answers - my question is - does the SA/SPG stand for (1) Stanley P. Gibbs or (2) Samuel P. Green, both were supposedly inspectors at Springfield Armory between the years 1936 - 1950, probably at different times. The rifle has all the parts of a 1931 era rifle except the WW1 hand guards and front "RI" markings. Information needed - Thanks

[7,62x51mm]

The 1903 cartouche is Stanley S.P. Gibbs who worked at Springfield Armory from April 1916 until Dec 31st 1951