The whittled down comb on the butt seems to be a Canadian thing and often seen of old trapper guns. Bubba had a great grand father. The story that I heard is that the comb was reduced to allow for getting one's face down to the sight line when wearing hat and the thick collar of a winter coat.
The Dominion of Canada stamp of DC marked within a diamond on the left cheek of the butt was applied by unit armorers with the use of separate hand stamps. Perhaps the armourer didn't look too closely at the stamp that morning, he used the G in error. Everything else about the marking is correct according to the published directives.
The rifle looks to be similar in type to that of the Sergeant's two bander.