In one scene, Anthony Newley and his pals go the cinema where a movie called The Cockleshell Heroes (1955) is playing. This is an inside joke; it was one of Newley's and David Lodge's earlier films.
At the start when Anthony Newley is being quizzed by reporters after a 'gig', one of the reporters with a one line speaking part, is Clive Dunn (Dad's Army (1968)).
The first of five films Newley made with Anne Aubrey and Bernie Winters. Newley and Winters also appeared together in The Strange World of Gurney Slade (1960).
"I've Waited So Long" reached #3 on the UK charts. The soundtrack EP reached #13.
Included in song credits is Gerry Laundan, who was in fact Jerry Lorden.