My question has more to do with the Chronomatic movement itself. We all know that it was comprised by a Buren microrrotor automatic movement and a Dubois Depraz developed chrono module, and that it was launched in 1969. Buren, however, went out of business around 1973-74, whereas Chronomatic equiped Heuers were available until probably the early to mid eighties.

Also, Calibre 7740 from ETA is clearly the same DD chrono module on an ETA manual wind movement. 7740 is the caliber inside some of the black PVD Monacos recently reviewed in this forum.

Does anyone has an idea of what is the story?