Something is not adding up with your CAD images. Unclear to me how the lever actually engages the striker. Are you sure it's 3-position?
The standard mauser safety has a shaft that goes forward and locks the bolt handle when in the lock position. It relies on a rotation to engage the locking feature. For the design below there is a cam feature which will engagae a spring loaded plunger to lock the bolt handle.
Fire position, spring plunger is not drawn but will dampen the safety movement at this point (red highlighted area). Cocking piece blocking pin is clear of the cocking piece in recess machined into the shroud.
Now the safety is moved to the safe position and the cam still has not engaged the bolt lock plunger. The cocking piece blocking pin is at TDC (top dead centre - automotive term) and the interferance you can see, means the cocking piece has been lifted off the sear. A shallow grove is also to be machined into the cocking piece to index the safety and hold it in that position.
To lock the bolt the safety needs to rotate further anticlockwise so the cam engages the bolt lock plunger. The cocking piece blocking pin slides across the face of the cocking piece until it contacts the shroud, which blocks an further rotation. As the blocking pin has moved beyond TDC the firing pin spring holds the safety in that position.
I hope this helps understand the function better, although my explanation could possibly be better. The weak point of this design is the bending force on the blocking pin. The interferances need to be tuned to minimise the activating forces, and I have added a boss onto the safety lever to better support the blocking pin, although aesthetically the boss is a challenge.
This photo of the 450Rigby appears to show a feature machined into the shroud to park the blocking pin in the fired position.
This photo (not that clear) appears to show the blocking pin moved over into the shroud when in the fire position.