If the bore is hard-chromed, it was a mid-production gun. The very early ones did not have a chrome bore, but when the Japanese army got into the Pacific islands, they quickly discovered that the bores would be ruined in very short order, because of the humidity and the corrosive primers.
I have one that was probably unissued, brought back by my father-in-law. It has the chrysanthemum ground off, which means it was a weapon that was turned into an arms depot.
The action is a modified Mauser action, and is known for its strength, at least in the early and middle war weapons. The later ones were crudely made and not safe for anything but hanging on a wall. The one I have has a sporting-grade blue on it. I only have one modern gun that has as good a blue, and it came out of the Remington custom shop.