unused Block Larger Than four OFFICIAL STAMPS: 4a. grey (setting IA) block of six (3x2) with inverted watermark, centre stamp of lower row showing error "GILDI" for "Í GILDI", with sheet margin at foot, centred to left otherwise fine mint (the lower row is unmounted). Believed to be unique. F. Tj22v1 + 22v8 (unlisted inverted). Photo in colour