I have asked this question before, maybe not here, but I don't think that I have ever gotten an answer.
I have a Springfield 1903 made in 1910, and it has the proper single bolt stock.
Problem is, the cartouche says CN1910. That means the wood was cartouched at Rock Island and is probably not the original stock.
There is an S stamped clearly on the muzzle end of the stock.
The rifle has a 1919 barrel, so it was rebuilt after WW1.
This is the way it came to me. The total wear of the rifle and wood is such that the stock appears to be the one applied at the time it was re-barreled.
I can see the stock being replaced and being nearly correct for the rifle, however not original due to the re-barreling, but there is the S stamping.
Was Springfield making stocks for Rock Island around 1910?