Sorry for the late reply.
There is a Noel Coward song, “That Is The End of the News” that has a line about shingles meeting in the middle. Not from the seventies obviously but it could well have been performed on TV around that time as there was a bit of a Coward revival going on (e.g. the revue “Cowardy Custard”). Jake is often compared to Coward, of course.