When Major Pott looks out of the man hole cover just before the tank passes over him, his shirt is light tan. Next shot when he is in the catacombs again, his shirt is brown.
When the German doctor examines Colonel Kastorp, he says he has been dead about an hour. When the Italians pick him up to take him away, rigor mortis has set in. Rigor mortis doesn't occur until up to 3 or 4 hours after death. It is unlikely that this amount of time occurred between the Colonel's death and the Italians taking him away.
Lackawanda? The town in New York is named Lackawanna. No "D".
Gina's hairstyle and clothing (including underwear) are of the 1960s, not the 1940s.
At minute 70, in the scene of American armored vehicles in a grove, one of the vehicles is an M113 armored personnel carrier. M113's did not go into service in the US Army until 1960.
The opening scene is a large assault by American soldiers who pass the camera and keep running up a hill. One of the soldiers has long, shaggy hair of the type that was popular in the mid-1960s. During WWII all soldiers' hair was required to be cut short.