> Bob Thomson, who lived in Cambridgeshire, did a great deal of research on the song as it was particularly popular in East Anglia - he turned up the information on the settlement on convict returnees around the Oxborough Hall area

OK, thank you, that explains how the name in the song became "Oxborough", that name being familiar to people in that area, including returned convicts, and thus replacing "Hawkesbury".

(But sorry for continuing the thread drift.)