"Bob's information is interesting but far from conclusive, or even the most likely scenario."
There is no "most likely" about song origins Steve - we simply don't know and have to base any guess on all the information at hand
Bob, despite his knowledge of broadsides, related the song to the Oxborough area and its returned transportees settlement, thus giving it an Australian connection
It doesn't mean the song was made in Australia, or even about a specific place there - it might well be that a singer/maker might well have chosen a name he or she was familiar with
"Most likely" is more a suggestion of competition rather than a friendly exchange of opinion and information.
Jim Carroll