I have looked closely at the WW2 Hunter that I got from you Ron, and as this knife was obviously a working knife, the keeper was cut into quite a lot, if it would have continued, it would have severed it. Also note the edge of the mouth next to the rivet where it has been sliced indicating an angled knife draw out of the sheath.
Do you have any idea when Heiser went to the slotted keeper attachment, and discontinued the use of a placement rivet? Perhaps done as a response to complaints to severed keepers? Or maybe cheaper option, no need for a rivet.
