Thanks, Kevin and Boho. I had quite forgotten about the Skylark version. Presumably, by Gerry O'Beirne you mean Garry O'Brian, who played frets and keyboards for Skylark.

Just to clarify the question of who wrote the tune, and because I'm too lazy to get the record off my shelf, I recall that Skylark used a different melody to the one with which it is usually sung. That, I guess, is what is meant by the sleevenote comment about Garry composing the air.