Hi,

TY Mitch and Richard. I've contacted Siobhan Miller, Brian's daughter and a fine traditional ballad singer. She's going to send the request of the source to her dad-- maybe she'll record his version someday. Here's a different version she recorded of the Twa Sisters:

Swan Swims sae Bonnie: https://www.bing.com/videos/search?q=Siobhan+Miller&&view=detail&mid=EF7E8A4389E283537C87EF7E8A4389E283537C87&&FORM=VDRVRV

Richie