I see I made an odd typo in my earlier post - I meant of course "Mormond Braes" - no Mormons of any description involved AFAIK.

I was about to insist that it must have been Roy who played the fiddle on Mormond Braes based largely on my view? prejudice? that Roy tended to be the more musically adventurous of the two, and that the number of instruments heard on Peat Fire Flame could be accounted for by double tracking.

However, I typed "Mormond Braes" into Google and a Youtube recording of the song came up as sung by the Corries. No visuals of course - however, the uploader had put together a string of photos. At 0:59 you can see Ronnie playing some kind of bowed instrument. A bowed psaltery??? See it here: https://www.youtube.com/watch?v=HtXfQVn1C-4