In 1949, in hommage to Jacques-David Lecoultre, who died one year before, we had the reference 2726, a very nice Triple Date Moonphase ( Credit pcitures: Zaf Basha )
Another example of the Tavannes movement and caliber can be found on page 30 and 38 of 'Jaeger-LeCoultre,' by Zaf Basha to whom we thank for this information.
Anyways, here dial looks good. Lecoultre doesn´t have a free to acces database. The Zaf Basha book is as close as it gets (and it doesn´t get you that far).
Among the greatest watches ever made by Jaeger-LeCoultre are the Mark 11 watches issued to the UK Royal Air Force. These were issued to RAF navigators and later to the Royal Australian Air Force navigators as well, and some collectors consider these to be amongst the finest military watches ever made. For more information on JLC Mark 11s, check out , which provides a ton of background information including serial numbers of surviving examples. This particular example was issued by the UK government in 1948 and is being sold by Zaf Basha (author of a great book on vintage Jaeger-LeCoultre watches) .