Have you looked at these? The second needs care, it's not sufficiently critical.

Gower (1976) Hershel Gower "The Scottish element in traditional ballads collected in America" pp117-151 and 208-211 of Emily Lyle (ed) Ballad Studies (Cambridge)
Tallmadge (1968) William H Tallmadge "The Scotch-Irish and the British Traditional Ballad in America" New York Folklore Quarterly vol XXIV no 1 (New York Folklore Society, New York, December 1968) pages 261 - 274