Hi Dan,
I found an earlier example. The triggers are on a wheellock rifle from Germany. I don't have time to scan the photo right now, which is on page 32 of Schedelmann's book "Die Grossen Buchenmacher". The date is 1580 and the maker is Peter Opel. It is a typical set trigger found on Wheellock rifles and some later Jaeger flintlock rifles. It has a short stout rear set trigger that slants rearward and a very fine hair front trigger. According to my history of the Graz wheellocks, examples of highly developed wheellock guns increased dramatically during the late 1560s and 1570s. Prior to that period they seem to be much simpler guns usually with simple triggers, button triggers, or lever sears like matchlocks. My guess is that set triggers were probably applied first to wheellock rifles perhaps as early as the 1560s. In my reference books, I have no examples of flint-using locks with set triggers until late in the 17th century.
dave
