The watch is actually from Dubey & Schaldenbrand: Index Mobile Watch
By: COUNT DE MONET : November 9th, 2019-07:11
It was a patented movement, based on a mundane Landeron chrono movement, where Prof. Schaldenbrand added only 12 or so more parts to make a split second chrono out of it. Starting (with a bit of a jump) is done with the pusher at two, splitting by pushing...