"In Scotland, as a kid, we used to sing:"

Yes Jim and of course the destination was normally England! I remember being on a bus in London with lots of my mates (teenagers and early 20s) during the 1981 visit to Wembley. The whole group were singing yhe words you mention

If I had the wings of a sparrow
And I had the arse of a crow.
I'd fly over England tomorrow
And shite on the bastards below!


It was then that this big black lady conductor got up. Perhaps she could see we were noisy but basically harmless - or maybe she was just very brave as there was about a dozen or so of us! Anyway she gave us a row for using such language in front of the other passengers so instead we sung.....

"If I had the wings of a sparrow
The posterior of a crow
I'd fly over England tomorrow
And poop on the people below"

Infantile humour but she saw the joke and burst out laughing (good humoured) along with a few of the other passengers.