I agree completely with you. Everything fits. I believe deliveries of most parts to the terminated wound down thru late winter early spring. They all knew in Jan Feb that it was over. So they ran their inventories down and purchased or swapped only what they needed to finish off what guns they could. Sights, if needed would, have come from local suppliers. IRCO north, Hemphill south. Hence the small numbers of these adjustables on the late terminated guns. We all assume that only the punch was used to secure adjustables. According to Ruth, IRCO and QHMC paired up to solve the problem of adjustables breaking loose. IMHO, I believe they initially used the same procedures to secure adjustables and flips. They didn't know any better. No new procedure would be recommended much less implemented until the problem manifested itself as more newer type sights were installed. I have an UN Quality from this time period with an IRCO T3 (geographically correct) sight. The staking is unlike any I've seen. 4 small punches very precisely and methodically placed in each quadrant of the dovetail. Almost as if they were testing to see what worked. Was it an IRCO/QHMC test gun? Who knows? Do I believe this adjustable sight is correct to the gun? Absolutely! Completely off topic. Watching news this morning. Saw footage of a Frenchicon cop in Paris carrying what appeared to be an M1icon Carbine!!! Oiler cutout, barrel and front sight unmistakable. Still going strong!