This has been released on an album this year... https://www.youtube.com/watch?v=msyYkrm-i5c
The album it's from is on Bandcamp...https://castanarc.bandcamp.com/album/water-from-the-well
It's from 1990 apparently. Not sure it's been on an album before and I can't see a reference to it in the Music section though I'm probably wrong.
The first album by Castanarc, recorded at Fairview Studio, Hull UK in 1983 and engineered and produced by John Spence.
This is the reissued version which was released by Khepra Records in 1998.
I used to have this on vinyl. I don't think that I ever realized that Bill played on it. He had dropped off my radar by then (until the early 90's).
The original cover