Yeah those old military triggers are tough I'm surprised he didn't polish up some of the trigger parts with all that work he did 🤔There should be some Japanese lettering visible on the top action, or perhaps a spot where some were ground off. I have an Arisaka in 7.7mm(.311" bullet dia.) that my brother and I converted into a deer rifle in 1973. He crowned the barrel and installed iron sights and I fitted a Fajen stock. Missed a buck of a lifetime, on a hill in Ravine, PA in the late 70s due to the 8# trigger and the ridiculous bolt "end cap" safety. No wait...it was my fault, should have not carried that rifle into the woods. Forced me to buy a Remington 760 and mounted a scope on it. Norma made ammo.
I see these rifles selling at gun shows so somebody wants them.
BTW the Arisaka came in 7.7mm and 6.5mm.