You've had several Scots including myself suggest that the singer doesn't really sound Scottish. Scotland is a small country and the folk community is quite well known to each other. Had he been a Scottish singer who was known in any way then I'm sure somebody (ie especially the likes of Jack) would know of him! I think North America is a better bet though even at that if he is someone who is only known in his home town etc then it may be a long shot. The guy might only have made several home made vids and not be a gigging musician.