For what it's worth, my first edition copy of The Wee Red Book (Norman Buchan's '101 Scottish Songs', from 1962) has 'The Wee Magic Stane' attributed to John McEvoy. The verse in question has "a stane wi' a ring" and the notes at the back of the book say "When the Stone of destiny was removed on Christmas Day, 1951, from Westminster Abbey it seemed for a time as if all Scotland was busy writing songs about the incident. Some of these songs were pulled together in a small publication called 'Sangs o' the Stane' (Scottish Secretariat). Of them all it is 'The Wee Magic Stane, written by Johnnie -sic- McEvoy, which has passed most quickly into popular currency."

And the acknowledgement page thanks FILMUSIC PUBLISHING CO. LTD. for the song.