The movie seen by Jim (David Essex) and Jeanette (Rosalind Ayres) at the cinema is Horrores do Museu Negro (1959).
The original end music, "That'll Be the Day", was replaced for the American release by David Essex's "Rock On", which had just been released.
Producer David Puttnam was impressed by Harry Nilsson's song "1941" and asked screenwriter Ray Connolly to create a screenplay based on it. The resulting movie resembles the song in all key respects, except a funfair substitutes the circus of the song.
It is rumored that Harry Nilsson made a cameo appearance in this movie which may have ended up on the cutting room floor.
There are two big Beatles connections that bookend this film. Firstly, right at the start of the film where Jim goes into the cafe a guitar instrumental called " Raunchy" is playing. This is the song that George Harrison played to John Lennon on the top of a Liverpool corporation bus as his audition to join The Quarrymen. The second is the Buddy Holly & The Crickets song "That'll be the Day" was the first song ever recorded by The Quarrymen, featuring Lennon, McCartney and Harrison.