SOUTH AFRICA 1966 (VARIETY) 7½C MAIZE CYL BLOCK, INVERTED RSA WMK
7½c Maize cylinder S21–S20 block x 4, perf 14 x 14, RSA sideways inverted watermark. Scarce. Fresh and fine. Mint never hinged. SG232var; SC294var; SACC231a
Note: the top of the RSA triangle watermark faces left when viewed from the back of the stamps