Thanks for your reply which is greatly appreciated. What I'm hoping for is some background information as to the story behind the Bison seen on the slab which I seem to recall has a Canadian reference. I wish I could remember where I heard more about these tiles apart from the fact that online they appear to be quoted as rare Whitefriars slabs and that mine, by implication, may be considered the 5th known example that's just come to light...bought a few days ago... hopefully someone will have something else to add..T.