I looked a long time, trying to identify this bayonet and still no answer.
Maybe the "experts" here can do it.
In the 2nd pic, the blade is folded half way.
https://imgur.com/0Ap3u6x
https://imgur.com/o0tnBRL
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
The 8" blade folds to the right when looking down on it. a bar on the side unlocks the mechanism.
The threaded stem is inline when the blade is in the straight, locked position.