Strange dagger ... can someone ID?

[fernando]

Originally Posted by fearn

Wonder if the ring is a way of securing the blade in a sheath? Perhaps you could lace it to the sheath, or use a toggle?

F

It's an idea; but the fact that the ring is practicaly placed at the center of the knife, obliges for its introduction well deep into the sheath, to avoid knife swinging down (center of balance is at gripo ferrule). I guess this (at least partialy) excludes the substance of such idea, right?
... This assuming there ever was a (conventional) sheath
Fernando