Nick, I had the same thought, that it might not just be guitars because of the sound quality which reminded me of the instruments you listed.

I just looked up the album credits for Jock Tamson's Bairns: The Lasses Fashion and the musicians are listed as:

Ian Hardie: fiddle [1, 4-8, 10], viola [1, 3-5, 9], bass [2, 5, 10], vocals [2, 6];
John Croall: bodhrán [1, 5-7, 10], vocals [2, 9], whistle [4, 6], bones [7, 9];
Jack Evans: guitar [1, 4-7], flute [2], cittern [3, 10], mandolin [5], bass [7], melodeon [9];
Derek Hoy: fiddle [1-10];
Norman Chalmers: concertina [1-5, 7, 10], whistle [1-2, 5-6], piano [9];
Rod Paterson: mandola [1, 5-7, 9], guitar [2-4, 8, 10], vocals [2, 4, 6, 8], cittern [7], trump [9]

Track 4 is When the King Comes O'er the Water (Lady Keith’s Lament) (Roud V42891) so the only instruments listed for track 4 are fiddle, whistle, Jack Evans and Rod Paterson on guitars.