Thanx to my query to "Ask the Gurus" (Bp to outsiders and spam blockers)
the tiles are soaking off in water (with a little coaxing) as suggested.
What is interesting is the fact that they were set on structural slabs
made up of laminations of green slate which look very much like roofing
slates. It seems as though they were prefabbed into panels and the
panels were then adherrred to the masonry surround. I'll post photos on
PTN Live soon and let y'all see.

Rudy

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