A coverall made by Osh Kosh, believed to be from the 1950s. Collar-less, same as the WWII era engineer jacket. It could be as well, but the pockets and hem are the same as the coveralls, so the collarless It was made as a coverall for the It is a piece of clothing that makes you feel that the specifications of workwear at that time were diverse.
The other engineer jacket was more like a vest with long sleeves, but the same collarless jacket with different pockets and hems made it look more like a coverall.
It has a small pivoting button. There are two button holes and the thickness of the sleeve tip can be adjusted. The buttons are not hidden like the other engineer jacket.