Verses six and seven are reversed in the printing at ingeb.
"According to Gavin Greig, this fine song was the work of William Scott, born in Fetterangus in Old Deer, Aberdeenshire in 1785."
He worked as a herd-laddie, as a tailor, worked in London, visited America, and returned to Old Deer, according to ingeb.

I have not checked the above.
Johnny Sangster

There is a note on Johnny Sangster at Musical Traditions: Mustrad News