As the person who first recited this poem on stage as part of the "Jumbo" cast in June 1974, I can say that Jim Smith got the story about its creation and first performances pretty right. He also got the words pretty close to true. I still have the original manuscript and the main difference is in the opening stanza, which reads:

In the back of donga country
There's a tale the old folks tell
'Bout a man who's [sic] name is famous
In the town of Bungadell

I'm glad the piece still gives pleasure. Rob Bath and Andrew Bleby deserve full credit for it.