Billy Pyle's "The Garand Stand Report" Fall 1994 No 16 has an article by Scott Duff "More On SPG" about post WW2 rebuild markings on M1 Carbines. Duff has a photo of a S.A. S.H.M. carbine stock during the tenure of Col S.H. MacGregor Nov 17, 1945 to Aug 9, 1947.

Also there is a photo of a S.A. over S.P.G. rebuild on another carbine which belongs to civilian small arms inspector Standley S.P. Gibbs used duing 1947 to 1951. It is not common to find the S.A. S.P.G. rebuild stamp on a carbine stock and I would consider it rare. I have seen another some years ago.