South Africa 1933 2d Block with Doctor Blade Flaw

1933 2d slate-grey & lilac (SG 44bw var/CC 44aa var). UM/M left marginal block of four, watermark inverted, showing strong DOCTOR BLADE FLAW down right hand pair of the block. Hint of brownish gum, fold in margin. Dramatic example of this inking error on this value.