Proof Block Larger Than four 10d. lilac, imperforate plate proofs on ungummed paper watermarked "4", a block of six (3x2) from top-left corner of the sheet, watermarked "10", a block of eight (4x2) in a deeper shade from top-right corner of the sheet showing plate number "1" in selvedge (diagonal crease in selvedge clear of the impressions); fine