Some similarities ;-) The story goes that Helmut Sinn and the Breguet family knew each other well ....
... and both had obviously strong ties to aeronautics. Powered by a Valjoux 88, the Sinn watch - based on my exchange with Helmut Sinn back in 2011 - was produced in the early-/mid 1970ies and Helmut Sinn estimated to have prouced only "a few". There is a...
Sinn multichron? Breguet astronomic chronograph ?
Mathey Tissot chrono triple quantième? That’s an unexpected resemblance, at least to me!