John Hamilton's song The Braes o' Bowhether (1796) uses the same melody and most of the lyrics of Burn's song And I'll Kiss Thee Yet (1788) AKA Bonnie Peggy Alison, and the tune used is called The Braes o' Balquhidder.
The lyrics of the McPeake's song The Wild Mountain Time/Purple heather/Will ye Go, .. are obviously derived from Robert Tannahill's Braes o' Balquhidder but the melody is different from that used by JH, RB and Tannahill which goes back at least to David Young's Collection of 1740.
Tannahill originally set his lyrics to The Three Carles o' Buchanan which Hamish Henderson erroneously described as the tune to which John MacDonald, "The Singing Molecatcher of Morayshire", sang the McPeake song. MacDonald actually sang McPeake's tune as well, originally recorded on the Topic label, 1975, but reissued on Greentrax, CDTRAX 9053, 1998.