I expect you're right, but a lot of background information does turn up in previous discussions, and I'd as soon not repeat it here.  The problem is that we don't know which version of many Skyvistascot is looking for; the doubling up of the title (I can't remember who started that, perhaps Child or Sharp) confuses the issue still further.  I'm guessing for now that the song wanted is Waly, Waly, Gin Love Be Bony (aka O Waly, Waly Up Yon Bank) -that is to say, the lyric song rather than the narrative ballad Jamie Douglas, in which part of it appears- which was published in Ramsay's Tea Table Miscellany (vol. II, slightly prior to 1727) and, in a slightly different form, in Thomson's Orpheus Caledonicus (1725; longer version in the edition of 1733).  One or other of those was probably the original source of the set you quoted above.

What appears to be the Tea Table text is given twice in the DT, at  WALY, WALY 3  and  WALY, WALY 2: The accompanying midi files differ, however, which is puzzling, and neither is that given in the Orpheus Caledonicus, though they are clearly close relatives. There is a set of sheet music available online at the Lester Levy Collection, "As sung by Mademoiselle Christine Nilsson in America", which appears to be a completely different setting: O WALY, WALY UP THE BANK..

Sheet music is available in plenty of modern anthologies; a quite nice one (containing the Orpheus Caledonicus set of 1733) is Wilma Patterson's Songs of Scotland (Mainstream Publishing, 1997; ISBN 1-85158-722-5). It's priced at £25, but is probably available in libraries, along with many other such books.