The picture of the Chevy posted shows only the bottom door hinge, where the original picture clearly shows 2 door hinges. I also believe the Chevy had front leaf springs as well, and the original picture doesn't show any front spring hangers.
Could be a different GM car, or maybe a Stude. Lots of late 30s and early 40s cars had a similar body style. Rear parallel leaf springs, and likely an independent front suspension with 2 outer door hinges will tell the tail.
We have eliminated a 39-40 Ford coupe, and the 38-41 Chevy coupe. I can add a 39-41 Plymouth coupe, they had 3 outer door hinges. Gene