Given the source where I got it, I believe it to be from the Greener Factory Collection. I have been trying for years to obtain a copy of the Navy Arms Catalog of their purchase of the Greener Collection to confirm this. I have another rifle of the same period/condition/source that has a 3/8 inch wide bevel cut on the left side of the receiver from the charger bridge to the rear sight pivot lug. I know the two former owners and they were not machinist tinkerers who would do something like this.

As far as information from the first war or any other source, the first principle of any large organization is that they don't believe any report that is not current. Many times at Ford I heard, retest it they might not have done it right or we have better what evers now.