Yeah the lack of original Garands in Canadaicon makes this tough. I have 474881 with the "7" on the cover and I've seen 474863 with the same "7" both Britishicon proofed. That and lack of documentation in books is what led me to start looking for more info on this. Bob said they are US marks and RCS says they marked the covers from mid 1940 to sometime in 1942. Is there somewhere that mentions this? Im curious to see more to try and find a beginning and end to these markings. Page 47-48 of Joe poyers book make mention of a punch mark but based on the detail in the rest of the book you'd expect it to mention obvious letters and numbers. Id love to attach a photo here but im not sure how to do that.