Obvious stunt double for Jim-Bob in long shots of Ben and Jim-Bob wrestling on the ground. The stunt double is a thickset tanned man with much darker hair than the rangy, pale-skinned and fair-haired David W. Harper.
At 23:03 Jim Bob takes Ruby Davis on a date and showing them playing a Gottlieb "Flying Carpet" pinball machine. "Flying Carpet" wasn't Manufactured until 1972. Much, much later than the time period this was to have taken place.
Grandpa scolds Miss Mamie for giving up on life but he did the same thing in S1E6 The Star.
Ben tells Jim Bob to tell mama not to set a table for him for supper. This makes no sense. He should have said to tell her not to set a place for him at the table for supper.