This still-popular song in John Farnham’s repertoire was written by Manchester songwriter John Bromley (b.1947) whose demo of Comic Conversation was the source for Farnham’s recording.
In a 2008 interview with ABC Radio’s Coodabeen Champions, John Bromley recalled that Johnny Farnham discovered Comic Conversation amongst demos played to him in London by Tony Roberts of Warner Bros, Bromley’s publisher.
John Bromley’s songs have been recorded by several major artists, and in the 60s he released singles on Polydor, and was backed by Les Fleurs De Lys on a solo album.
References: 1. Interview with John Bromley, Coodabeen Champions Sunday Night Program, ABC Radio (Australia), 9 September 2008 (no longer archived at ABC site). 2. Brief Wikipedia entry on John Brumley. 3. Les Fleurs de Lys at Magic in the Air. 4. John Bromley credits listed at at Discog.com.
Thanks to Lee Skaftouros for suggestion.