[David_Hayward (RIP)]

That photo is definitely of an ACK-353, late 1939 on production as a 1940 Model, US military production. However, note that the possibly 1941 Model has 'GENERAL MOTORS TRUCK' on the side..and the grille is different. Must check further to confirm MY.

I am sure the French GMCs were in the first batch of 2,000 [later there was one ordered for 7,000] assembled from early 1940 by GM France in Gennevilliers with 450 workers. Production was continuing until June 11 when work stopped.