I have an interesting challenge for y'all. My father-in-law recently purchased this folding knife at an estate sale. He is a pretty experienced collector but he is uncertain of it's origin. He and others believe that it is Japanese based upon the markings carved on the stag handle. It has been referred to a rope knife based upon the shape of the blade. Unsure if it could be military but it reportedly came from the estate of a WW2 vet and was presumably brought back around that time.
I am posting it here to see if anyone can add any info about it.
Notice the interesting hallmarks....
Thanks in advance for your help,