Did you ever find the files you were going to look for?
I read in an old issue of the National Geographic that the McBeaths were descended from the Vikings who raided the west coast of Scotland and settled in Garlich.I visited there a few years ago and found nothing to connect to my McBeaths of KY.
I also visited the Isle of Skye and went to the McDonald Center.There was a large poster in the Museum showing the McBeaths as hereditary Doctors of the McDonalds.
The McBeaths do not have their own clan.They are members of the McDonald Clan.
If you found anything to connect you to the Russell Co, KY family I would like to exchange info with you.