The, usually reliable, campybike.com claims that this leaflet was released in 1984, and marks the launch of the Campagnolo Triomphe groupset. This document has no printed date, but campybike.com's date feels right.
The photos look, on first glance, to the be same as those in the 1985 Campagnolo's catalogue n. 18 bis. Bizarrely, they are very slightly different, but they show the same two derailleur models. These first versions of the Campagnolo Triomphe are shown with the distinctive plastic slice embedded in the outer parallelogram plate to stop the adjustment screws from loosening.
Browse associated derailleurs.