>>630718
It's a rare Jinsen Arsenal (curr. Korea) blade of probably mid-to-late war production; the guard is simplified, and the blade is parkerised, both indicative of a mid/late war production. Missing the stopper button.
The wooden hilt is either severely degraded or replaced, and I don't think the screws are original. Either way, it's a good find, and the blade is definitely authentic. Jinsen arsenal bayonets are very hard to find iirc.
http://ohmura-study.net/810.html