Lot 70505 – 1912-13 £1 Colour trial in yellowish green in a deep shade, a stunning mint nh corner marginal block of six

1912-13 £1 Colour trial in yellowish green in a deep shade, a stunning mint nh corner marginal block of six from the lower left of the sheet from the experimental printing on Joyson paper each overprinted « Cancelled » type 24, the selvedge at foot showing part of the « Postage » watermark inverted, fresh beautiful colour, a major Seahorse issue rarity, ex NPM archives (SG £19’500 as singles).