Lot 70570 – 1959 Wildings 3d deep violet « Dollis Hill Phosphor Trial » perforated bottom corner marginal block of nine

1959 Wildings 3d deep violet « Dollis Hill Phosphor Trial » perforated bottom corner marginal block of nine on gummed crowns watermarked (upright) paper, the first column without phosphor, the centre column with a 2mm blue phosphor band at left and the third column with a 2mm phosphor band at right that is misplaced to the right so that 95% of the band is in the sheet margin, most unusual and scarce (SG Spec. ST7(3)b, £3’150+).