Breitling ref 765 AVI all black 1955
Some sources also site the French Airforce as origin for the extra 3 digits. 1 Italian forum
http://orologi.forumfree.it/?t=63469678 and 1 french http://forum.chronomania.net/mix_entry.php?id=203319#.UpiMHHdFbwk "the number of French Air Force assignment engraved on the back (52x) Probably this serial was attributed to a military laboratory as cataloging, with subsequent delivery to the various department, For many years this type of watch and follow and 'the 2nd I see with the assignment (at this time and the other' in the network and the owners have pointed out that 'the first time I noticed the attribution of this model)"
How and where these fit into the Military categories for either French or Italian Airforces is currently still unknown and uncertain and needs to be investigated, also proof needs to be provided before this can be accepted as fact
in 1952/1953, the unproven rumors go, Breitling was in intense negotiations w/ the French Airforce and the AVI was developed based on the ref. 765, adapting the 30 minute counter to 15 minutes and adding the 12h bezel – prototypes or a small series were delivered and then the political connections of Breguet/Vixa changed the tender specs to add the flyback functions and Breitling lost the contract. Unsubstantiated, unproven and probably unprovable today, as most corporate documents were not passed on to the new trademark owner, Mr. Schneider. Probably still lying somewhere in a safe