Great Britain 1970 Queen Elizabeth II British Rural Architecture. 1/6d. greenish yellow, black, turquoise-blue and lilac. Bottom marginal example. Error, ‘turquoise-blue omitted’. Superb unmounted mint condition (with normal for comparison). David Brandon Certificate No. 40,112 (2009). AN EXCEEDINGLY RARE AND IMPORTANT ERROR OF WHICH ONLY 6 MINT EXAMPLES EXIST. AN EXHIBITION PIECE.