South West Africa 1924 KGV 10/- Type IIIA Plate No1 Block UM

1924 KGV 10/- blue & olive, Thinner Print Setting IIIA, 14mm between ovpt (SG 26var/CC36). Superb UM PLATE NO1 CONTROL BLOCK OF FOUR from the top right corner. A rare Plate No piece from this issue, a maximum of only 180 control pairs (of which 45 in each position) ever possible.Top right stamp with extraneous ink dots above "A". Fresh, vibrant colours, an exhibition showpiece, particularly elusive UM. Photo-cert: PFSA. (CC 36/cvR190000). See additional images and of certificate.