I don't think the 'scottified' version I knew was in any way dubious -- it led me to the original song / composer, but I still treasure the Scottish version for personal reasons!
I have a friend who is a songwriter and long ago he accepted that songs take on a life of their own once out there in the public domain- a bit like grown up children I guess!
I still get ragin' when I see incorrect youtube renditions of Iain's songs - but most of those people have never actually heard the original!
And - I should not complain since I frequently 'adapt' songs to suit my own vocal range / poor memory etc. - Folk process?!