Belgian dark blue jacket, most likely 1960s, made by great Belgian brand Gevaco. M/L size (23" pit to pit). 
3 patch pocket (please note the V shape stitching for the chest pocket), 4 front buttons, one inner pocket, lapel style collar, locker loop, sewn in back belt, longer length (longer than your usual French jackets).
Nice Gevaco inner label featuring the Gevaco donkey in its dungarees.
The cotton has the weight of a normal workwear cotton but feels like a moleskine, with a tighter twill.