I'm afraid I don't really know Hamish's version that well, I heard it just the once on 'Folk on 2' some years ago. I have the manuscript that Murray wrote, which I'll dig out and scrutinise.
Murray wrote a tune for the first verse which then changed for the rest of the song, the first verse version was to act as a clarion call to get people's attention and to be honest I'm not sure how accurate my rendition is to the original. (My musicality is such that I know I wonder off key occasionally, which I usually try to mask by pretending to sing under stress at having forgotten the words.)
Murray wrote it very quickly, he told me, in the loo at a pub sing-a-round where a lot of people were forgetting the words. To aid his memory (it's not a song on which you want to get wrong!) he made each verse start with words so that their initial letters were "M" "L" "S" "O" "S", his initials and SOS, for obvious reasons. It does help the memory process.
Bless him, he once took a week off work to redecorate his flat but instead committed all the tunes to the songs he had written to manuscript, which I now have. He never did finish that redecoration. He would be really chuffed at the interest in his music. He was a dear friend and I still miss him. I really ought to do more of his stuff, a fitting tribute.