You can hear the Corries singing THE LOO SONG at YouTube.

I believe they sing "Pappy hailed from timber too."—but I approve Taconius' changes, and I agree with his corrections.

This is an odd song. It seems to be trying to sound American, but Americans never use the word "loo."

Is the tale of George Washington and the cherry tree well known in Britain?

I think this fits into the category of Jokes turned into songs. I'm sure I've heard the story told as a joke, but I've never heard the song before now.