The song is certainly older than 1993 'cos I remember singing along with it at LLantrisant FC back in the early 80's. I'm pretty sure that Mick Tems was the originator of the lyrics and that it had been written for a play.
Llantrisant is pronounced Ch(as in Loch)-lan-tri-sant
"ach a fyi" is an exclamation of disgust, roughly "get away"
The gates to Dr Prices house can still be seen as you go up the A407 to Pontypridd and the site of the cremation of his son stands on the side of LLantrisant Hill just to the west of the town.