At the Glasgow / "Glesga" page at ukpals.com website, there is a comment from songwriter Harry Hagan. I'm copying it in this post.

Sam the Skull
This song was written after observing the antics of the cat population in the housing schemes in the east end of Glasgow (this was during my time as a painter and decorator with the Glasgow district council). It was first recorded by the folk duo Gaberlunzie and then by Alistair McDonald. Reference to the song can be found in the book "The People's Palace Book of Glasgow" and the lyrics and music in the book "One Singer One Song" published by Glasgow City Libraries. I was brought up in Craigpark in Dennistoun (where the library is) then moved to to Carntyne, went to school in Shettleston, and am now retired and living in Sandyhills (next to St. Pauls Church). I am married to Frances and have two daughters, Carol who lives in East Kilbride, and Julie who lives in Devon. Regards, Harry Hagan Sept. 2004

Then Harry Hagan posted a videotape of himself at home, with guitar, singing Sam the Skull. When a YouTube viewer posted a complimentary comment, Hagan posted a response in the comment section:

"I found a tape lying in a drawer I'd made about 3 years ago, and I decided to post it on YouTube. I have suffered a stroke since, my music and my grammar has affected. But I'm fine,
Cheers, Harry."

https://www.youtube.com/watch?v=QEX7G3MLKpo