There should be some information available from John Rice Irwin at the Museum of Appalachia in East Tennessee. I believe he has several in his collection. The mouthbow was played here in Stone County in the early part of the twentieth century by a Charlie Everidge. That is where Jimmy Driftwood learned the instrument and there is a story circulating in these parts that Jimmy taught the mouthbow to Pat Sky who in turn taught it to Buffy Ste. Marie. I am passing this along as a story. I cannot vouch for the truth of it. Charlie and Jimmy's dad, Neil Morris, were recorded by Allen Lomax and the song with the picking bow played recently on Spud Mountain via the internet. There are supposedly drawings on a cave wall in Europe, France, I think, dating back many 1000s of years depicting a caveman playing a mouthbow.