I enlarged the plate as much as MY computer would give any readability, it could be Delaware ? hard to make out. Someone with good equipment could do it .. also check who owned the house w/garage from 30 years ago.
Ed, it’s a Delaware plate from 1940, expires 3-31-41. In 1940, the DE plate was yellow with dark blue numbers.
There is a small sign under the plate close to the bottom bumper. You might blow it up and it could tell you where the car was sold. (maybe)
A higher resolution scan would be a big help. Images posted in this format here are generally smaller for quick loading. Unlike shows such as CSI, reality is - you cannot add details that are not captured on film (or in a scan or digital photo). You can interpolate - but that is a crap-shoot based on digital guesses.