The way I first heard it was a little different. The story line was the same but the chorus and refrain was made a little easier for people to sing along to. Still doesn't make sense but at least the words are real(ish) ;-)

Hey Roger Rum, Hey Roger Rum
Skin of a Spanish Onion
Oh, what a funny 'un
Glory Hallelujah, Hey Roger Rum

There was also an additional first verse -

There were two Jews who both came from Jerusalem
Glory Hallelujah, Hey Roger Rum
One was rich while the other he was poorium
Glory Hallelujah, Hey Roger Rum

Cheers

Dave the Gnome