Might be worth having a look at Bert Lloyd's notes in Penguin No 1. They are expanded in the reprint 'Classic Folk songs'. Old George Dowden from White Lackington Dorset had the song. He was a character, a retired sea captain who used to sing in the Blue Vinney Pub in Puddletown in 1908. I came across a Newfoundland version of the song decades ago and recorded it, and there is another in English County Songs (Lucy Broadwood) It might be worth seeing what Lucy B. has to say in the Journals. They are all available on line. Sorry for the rushed reply. If you have any questions please ask.