It may have been written by Mike Brewer and/or Andy Dutfield who were at Bede College, Durham (n.e. UK for the non UK based) from (roughly) 1970-74. I was there from 72 to 75 and they were certainly performing it circa 72. Whether they wrote it I couldn't be sure but they did some 'own material'. Somewhere I have a recording of it.

I think its Glamorgan not Glen Morgan. From a very long ago listening i think the lyrics are pretty close. I'll try and find it.

Mike Brewer was (I believe) sadly killed in a car crash but I think Andy Dutfield is still around although I have no idea ifhe is involved in music.

They also did an excellent (re-write?) version of Long Lankin.

Nick