These grills were only on '1971 340 cars and Twisters. They were also on the '72 340 Dusters. Not on the '72 Twisters. I have seen enough original ones to know. The Twisters with rallye wheels did not come from the factory with trim rings either. I have a '71 Twister and know exactly how it came.
I have never seen a 340 Duster that was original wearing hood scoops either. Not available. The scoops were a Twister item.