Sean,
Thanks for posting the ballad, but something is not clear. You first mention the manuscript which is fine, but then at the heading of the ballad text you put 'Broadside Ballad' and 'Tune The Dolphin'. Where is this broadside and when you state 'The Dolphin' do you mean that is one of the tunes which it is sung to nowadays, or are you suggesting that the tune 'The Dolphin' existed in 1746? Just somewhat confused.