Back in the day I did a few stuffer plates for Hummers and similar.
For pins, I used short lengths of aluminum nails. Mike their OD and drill slightly smaller. Put the stuffer plate in the recess and drill for pins along the joint line so the drill is half in the stuffer and half in the plate. Tap the pins in place, then remove the stuffer and file the top of the pins off flush with the case joint face. The pins are just there to hold the stuffer in radial location. The recess in the case holds the stuffer in place axially with respect to the crank.