This is RSA (South Africa) 1974-1977 Lot of 30 Blocks MNH 2nd Definitive 4c thru 10c Control Blocks of 6 from different printings between 1973 and 1977. Please look carefully at each piece-----Pane, Printing, Date of Printing, Imperf. Side Margin, Imperf. Bottom Margin. Finish very good.