Interesting designs. Appears the ones with just one screw, the screw location is more towards the front (which makes sense because of the recoil) and the one's with a tang screw plus a TP screw locate the tang screw more towards the back.
After looking at these pics I cut my tang down to two inches. Because this will be a 45 cal it won't have the recoil of say, my .50 or .54 cal so I'm thinking just one through the tang and into the TP will suffice.
But thank you all for the post and pics. Very helpful and informative.