Sixth issue, Ryal, mm. A on rev. only, reads H IB, sail furls 2-3, 7.70g/10h (Brown/Comber B2; Thompson O1/R1; SCBI Schneider 784 and RCL 3277, same dies; N 2004; S 2530). Very rare. Ex Walter Wilkinson, bt Spink December 1956.  Images courtesy of DNW.