I just bought what I was told was a Kai Gunto from a WW2 collector, but I have never owned any real Japanese weapons from this era before and so I have no idea what to look for.
It came with an allegedly real naval flag, and I was told that the collector was sold the sword and flag by the family of the officer who originally possessed it. The family that owned this also sold the collector a uniform, but I was unable to buy it at that moment -- if all checks out, I will certainly return and purchase it soon so I don't separate this officer's belongings!
My main concerns are that the blade appears to have either never been sharpened, or only lightly sharpened in the past. I also can't really tell if the ray skin is fake or not. Right now I only have a few (bad quality) photos, but hopefully this will help!