Recognize this bayonet?

[Cold Warrior]

I picked up this bayonet at a gun show last week.
The guy I got it from thought it was Swiss.
Can you give it a positive I.D.?

 

[diopter]

For Stgw57.

 

[Cold Warrior]

Bullseye

Wow, you got it with your first shot! I knew I could count on my 'Nutters to zero in on it purty quick.
I've got a K-31 c/w nice bayo, but this one has a totally different attachment design.
thx 4 the quick reply.
CW

 

[Daver_II]

I have a similar one... Longer blade though.