Oui c'est ce qui me parait probable, après je penche aussi sur la piste du M2 KS15-4 le numéro de série correspondrait
"Here is a description about this specical M2.
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This is very rare version of M2. Only 875 units were produced for the U.S. Military during Vietnam War, which later became the M2-R designated for civilian use.
The valid serial # range is: 1163150-1163770 & 1164046-1164300.
The M2 KS-15(4) is considerably rarer -- five stars in the leica guide as opposed to four for the M2-R."
“.Leica M2-R ... A minor change type that incorporates the rapid loading mechanism of the Leica M4 at the end of the Leica M2. Two lots of 876 units with serial numbers 1163150 to 1163770 and 1164046 to 1164300 were manufactured as the US Army KS15-4, but they were canceled and became a hot topic in the market. The model name of the warship department was only "M2", but later New York Lights ordered the same thing from the German headquarters, the model name in the warship department became "M2-R" and the serial numbers 1248201-1250200 were assigned."
https://f22cameras.com/en/leica-m2-ks15 ... y-silver-2et
https://tamarkin-rare-camera-auctions.l ... -ks-15-set