Btw can someone please explain the difference between a modular and an integrated automatic movement. While Breitling claims to have had the first modular self winding movement with the 1806 (read modular automatic movement somewhere), Zenith claims to have built the first "integrated" automatic movement.

Is that Zenith just doing a play on words since it lost the prize to be the first auto movement in the market?

Not relevant to this thread, and plenty of discussions elsewhere here and on the web about Zenith El Primero vs. Heuer / Breitling / Hamilton / Dubois-Sepraz Calibre 11, but integrated means built as a chronograph, modular means built as a time only with a separate chronograph module attached.

claim is correct, though actually Seiko might have been the first in mass production.

So guess is just a play of words by Zenith to confuse people.....

Thanks Fred, that's surprising!

By a whisker (a few weeks). Check Seiko cal 6138. Integrated or not, 3 features stand out on this most venerable of Japanese movements. Crown on the right hand side for case, full external rotor and day date windows. Day date does a double shift so it either reads; Other language/Kenji and quite an interesting feature for its time.

It’s an ordinary movement, nothing to see really (except planted bridge), and just as we have come to expect and see from movement development ever since. Watchmakers find them easy to work on. No booby traps or difficult to service parts, absolutely bullet proof and highly reliable.