I am tempted to say that the one visible complex Japanese Character is “Showa.” It looks a little different than how it appears on firearms (Type 14 pistols), but the basic strokes are there. “Seal writing” or the characters used with metal die stamps, etc., are often simplified from the way they would be formally written by a scholar. Usually, in Japanese, a plain cross is the numeral ten, but that cross doesn’t look anything like a Japanese “ten” as normally stamped, and is not even really oriented right. It seems quite crude in execution compared to the anchor and the other character. In the shadows, I can make out a huge circle with what appears to be several lines inside it. Have no clue what that means. “Translation of Japanese Ordnance Markings”, August 1945, A.S.F. Office of the Chief of Ordnance, Washington D.C., was not much help, even though it has hundreds of characters and combinations that appear on ordnance. A better photo would probably be helpful, but not to me. I note a new thread on the Forum on Japanese boxes, and the person who submitted it appears to have access to a translator. Perhaps he can help here? Why not try a PM to him to get his attention to this thread?