When Mary Ellen and Curt are talking on the porch at around 52 minutes, there is a shot showing a car brake rotor in the background. They were not around in the 1940's.
If fabrics and nylons were rationed during those years, then please explain how all the women have new clothes and stockings.
When Mary Ellen goes to turn the outside lights on, both switches are in the down position. There is a click and the lights go on, but both switches still stay in the down position.