So I took this technique further and rolled out two bags of 12.5 KG crank clay. It took an hour per bag (need a slab roller) . I laid it onto brown paper for moving and trimmed it. I tried to get closer to the original intention by embedding organic matter into the surface more and also pre fired raw clays as grog. In diameter this is around 20 inches ! I pushed the thinking around Sculpture/ drawing by taking out sections and working the interior too. This breaks the visual plane.