Watch List notes:

Mary, half bawbee, first period 1542 – 1558, open crown variety, open crowned thistle dividing MR, type Da crown but no arch, type Daiii letter M, MARIA D G R SCOTORVM, no inner circle or stops, rev. voided saltire cross through crown, cinquefoil below, OPPIDVM EDINBVRGI, no inner circle, wt. 0.63gms (S.5436), fine very rare
*ex Stack's, 28/04/2010, lot 1470, purchased for £253
This coin not recorded by Stevenson or Burns, but notes taken from Robert K. Stevenson BNJ 1989
None in NMS: SCBI vol. 58 or vol. 35
DNW 55, lot 55 for same obverse die

Estimate: 150 - 200 GBP