In case anyone's interested, I posted this request on the New England Bluegrass list (run by the Boston Bluegrass Union) and got a response from someone who knew Pete Roy and his wife and had contact information.

Pete was from Massachusetts and died several years ago. He was apparently an accomplished musician who wrote many songs and attended many festivals. I spoke to his widow, who gave enthusiastic permission for me to use his song.

And what a great song it is, capturing the love of the southland and coming from a yankee!