Dannyl, I looked at your pictures again and your bolt should cock on open and not on close, the angle cut in the rear is supposed to cam the lug on the bottom of the bolt back and into a rounded indent that holds it cocked. My thought are that the indent may have worn where it would not hold it cocked and a previous owner ground off the inside of the prong on the cocking knob to keep it from uncocking with the action open. I've heard of the ident wearing to the point it will not keep the bolt cocked and that becomes a real problem, you need two hands to close the bolt, one to turn the cocking knob to the correct position and hold it and one to then close the bolt.
