I have to re-lay about 15sq m of 1 ½ inch thick 9 in square red antique Norfolk Pamments, a softish clay tile like terracotta with lovely variegated colouring. Many are worn with the footfall of a century and a half and upon re=laying widespread lippage will be inevitable. They are to be laid on a screed floor in a hallway with underfloor heating. Is this material suitable for grinding after laying with a floor grinder? If so what sort of grinder and abrasive pads to use? Wet or dry? Before or after grouting? Would it be feasible to cut the pamments horizontally to make two ¾ in thick tiles out of each with nice flat surfaces? I haven't found anyone with the machinery to do such a job so far. Any opinions, thoughts or recommendations appreciated.