I'm the Steve Parkes who would have shopped Barrie, according to his earlier post up there. We sang together as a duo for several years, and before that I was a member of the Songsmiths club from around 1970. I can confirm that he wrote the song around 1971 or 1972 (and I've got BOTH editions of the broadside). The tune was actually based on the trad Moses of the Mail (as the first published version states); The end of my old cigar was the starting point for the tune of The knock on the door in the night squad, recorded (and acknowledged) by hamish Imlach.