Should probably also contact Lucy Macrae at Edinburgh University who has made a particular study of Borders ballads; she was also responsible for putting together various concerts and lectures re "The Borders Minstrelsy" at Innerleithen Music Festival. You might also pm Diva on this site who sang some of the songs. But not sure if these concerts were recorded: they should have been!
http://edinburgh.academia.edu/LucyMacRae