The average distance between the principle points for the large scale map is approximately 0.57 miles, roughly 3010 feet.  The average distance between the principle points of the small scale map is 1.33 miles, roughly 7040 feet.

The length and location of the principal points  and flight lines are different because the altitude the plane was flying at were two different altitudes which changes the area in the photo.  Since the small scale map was flown at a higher altitude showing more area, the time between pictures could be longer.

The lines of both flights change at least slightly.  The large scale map does not change as much as the small scale map.  The line changes in the 4th principal point because the specifications said that they had to avoid clouds.

The scenery between the black and white aerial photos from the 70s and google maps aerial photos are drastically different when it involves the patterns of the fields and the size of the orchard.