they sent this to me:
Well the sword was my grandfather's it came back with him from Papa New Guinea when he was a forward observer in the Red Arrow Division during WWII. The authenticity of it was that he got it from the regiment Commander, during war which he ended up with a bronze star from that time. It's hard to see with the phone as unlike normal factory soldier WWII swords that are stamped, regiment commanders brought their family swords so it isn't stamped. I used AI to translate it and that's how I got the name of the regiment Commander, he is well known family in Japan, his family is still in politics. I do have a charcoal of both sides of the tang, but would have to get that tomorrow as we are busy tonight getting ready for work etc, and have clients in the morning. But would be happy to get that tomorrow for you.