William and Mary (1688-1694), Halfpenny, 1694, struck on a Charles II Halfpenny (BMC 606, this piece). ROLO of CAROLO visible above busts,  exceptionally rare; perhaps no other specimen known.  Ex George Bates, provenance: C.W. Peck Collection, SNC December 1969 (10065) [from Seaby]; G. Bates Collection, Glendining Auction, 30 April 1986, lot 283 [from B.J. Dawson March 1978], images courtesy of DNW.