Great Britain 1902 King Edward VII Inland Revenue Officials. £1 dull blue-green. Left marginal block of four. Superb unmounted mint condition (folded through perf. and margin hinge strengthening minutely onto stamps). Holcombe Certificate 7,211/92 (1992) and British Philatelic Association Certificate No. 40,032 (1993). THIS IS A PHENOMENAL PHILATELIC RARITY – UNIQUE AS A BLOCK. OUTSTANDING AND EXCEPTIONALLY RARE.