The version of "Not Now John" is clearly the radio-friendly single release, presumably so that the video could be shown on outlets such as MTV. This version of the song contains the echoing refrain "Stuff all that" whereas the album version repeats "Fuck all that".
The album "The Final Cut" was originally intended as a collection of songs from the movie "Pink Floyd: The Wall (1982)," with one working title being "Spare Bricks." Then the Falklands War broke out between England and Argentina, and Roger Waters changed the album, the only Pink Floyd album with all songs credited to him, into a protest against the War.
Alex McAvoy also played the Teacher in "Pink Floyd: The Wall (1982)." The album of "The Final Cut" grew out of supplemental songs recorded for a soundtrack for the Wall movie. As such, it deals with many of the same themes.
The name of the psychiatrist, "A. Parker-Marshall", was a swipe at director Alan Parker and producer Alan Marshall, who Roger Waters fought for creative control during the making of "Pink Floyd: The Wall (1982)."
Director Willie Christie was, at the time of this film's production, the brother-in-law of Pink Floyd lyricist Roger Waters.