Three of these unfinished Mother-of-Pearl plaques can be found on page 117 of Ralph Tegtmeir's 1987 book "CASINOS." The author thanks Christian CARO of Maison Caro, Paris, for his help in showing pieces from the Caro Collection; of which these pieces are now in Robert's and my collection. The reason for the clipped (coupé) corner is for stacking purposes against the wheel.

(We are actually looking at the reverse of the piece.)