They most likely just re-shot the film regrouping the cels into the shot as necessary.
Another example of a differently shot AR film is
Seven Brides for Seven Brothers. They shot a CinemaScope version and matted widescreen version (1.85:1) at the same time (camera's side by side.) So the different of the film are at slightly different angles.
This DVD Beaver review gives you an idea of the difference between the CS and NA versions (though the DVD NA version is cropped slightly differently.)
Seven Brides for Seven Brothers different AR comparison