ABU DHABI – 1966, 20f on 20np Bright Ultramarine – Worth US.$5,250

Perf 14-1/2, Inverted Surcharge (17b; SG 17ba). Used with 50f on 50np (20; SG 20), vertical pair, all tied by Abu Dhabi Jan. 26, 1967 circular datestamp on registered cover to Surrey, England, Very Fine, exceptionally rare in used condition, even more so on cover as only four examples were postally used according to Donaldson, catalogued as used single, SG £1,300