Burns' words are not exactly the same as those in the Manuscript, but the song is recognisably the same.
The Manuscript seems to me to have been the same type of thing each of us (of my generation at least) did as youngsters getting into folk /traditional music - in the days before the internet!
I would hear a song on the wireless, or someone singing at a party or concert, scribble it down in a jotter....still have my wee book from schooldays in the '60s, and the follow on ones from student days,and then 1970s, 80s. Not the beautiful handwriting of E.St Clair, but the same idea - noting down songs and some poems I liked, wanted to learn - as for the tunes, they had to be picked up by ear, from singing choruses then gradually memorising verse tune....they have stayed with me ever since!!!
I am sure many people down the years have done the same, but probably most have been lost or discarded - we are so fortunate that the St Clair Manuscript has been preserved, and that Ronnie has made it available in a format that is easier for most of us to read!