Toward the very end Remington offered the single trigger on the Trojan, but the records only show that 27 Trojans left the factory with a single trigger. Most of the evolutionary changes to the Parker Bros. hammerless action had been made by the time the Trojan was introduced in 1912. Early Trojans had a useless rib extension that was eliminated on later Trojans, but I don'k know of any difference between a "DuPont" Trojan and those made in Meriden in the late 1920s and early 1930s.