To address what I believe the question was, (the plausibility of provenance) I would say the knife fits well in the time frame and the documents appear original. Although not enough to unquestionably link the knife to the man, it's enough to certainly warrant digging a bit deeper, and a better start than no provenance at all. The shape of the blade of course is apparently altered, but not a far cry from what a marine raider might visualize as the perfect combat knife.