Hm! Tried posting this and it disappeared. Fortunately I had done a CTRL-C.

Yep, that's the song, albeit with some lyrics switched around, as you say. Many thanks! The 'Cat delivers again.

Between that and what I remember I can (re)construct something close to that original recording.

If anyone who reads this is in contact with Phil himself, please point him to this thread and ask him whether he remembers singing the song in Edinburgh. It would have been around 1970, give or take a few years. The story about the monkeys would be worth repeating too.