Immaculate or too good to be true? https://www.sellingantiques.co.uk/3...agship-101-30l-chronometre-mens-watch-c1955/#
Longines30L.com is probably the most comprehensive resource for the dial variations of 30L Flagship chronometers.
Yes, the dial is not correct, but the movement does appear to have the correct chronometer balance. Here is mine as a reference, and it has been confirmed by extract.
Actually, as Longines has confirmed with my example, there are 2 variations of 30L chronometer movements. Examples before the late 50’s should have a Breguet overcoil. Examples after this time, however, may be outfitted with the standard balance spring.
If we go even further into the weeds, Longines also made 30L movements with Breguet overcoils that were NOT chronometer certified. I have an example of one of these movements as well. There is more detail on 30L variations on the thread below. https://omegaforums.net/threads/longines-30l-variations.95910/