I went to D.C. on my honeymoon and toured the Spy Museum they have there.
They have examples of a bunch of cool small knives.
However, I don't remember one of these.
They did have a small hooked blade, think of a can opener on a swiss army knife that is a sharpened blade, it was used to slash or cut any type of fuel line or cable on a car truck or train.
The operators would be trained on how to get close to targets and use it so that it would slow down the enemy asset yet not be obvious to an observer.
Really neat stuff.