Concise and exhaustive – very impressive, Nicolas!
The only question that lingers: why did JLC mark only some of the 24000-42s as “CHRONOMETRE” on their dials but not all of them – extrapolating from the pictures that can be accessed on the web it might even be just a minority of these chronometers that were marked as such on their dials. I still do not have any idea how to explain this inconsistency.
Best,
Christian