The story about "first prize" I heard from a pal of mine in 1954; he got it from his father just a bit previously [in the West of Scotland, this was]. As for the other anecdote ("gruesome" pun), I heard that as a mere joke told by a young fellow in the Royal Navy, Spring of 1952, in England (he probably got it at his public school not too long before this). I'm tickled to see both of these tributes to the Scots nation immortalised in song.