Of the mere fifteen examples of this rarity known to exist, this still is among the finest appearing of the potentially thirteen in private hands, as nearly all have faults much more severe than this example; of the original fifteen recorded examples (the top row of one sheet of 30), it is known that at least two pairs were extant (positions 11 and 12) which is in the Royal collection and the end pair (positions 14 and 15) which may or may not remain intact as it has not been seen in decades; a highly important stamp to the serious collector of British Africa, not to mention a key stamp for the dedicated collector of Inverted Centers of the World; ex-Cunliffe (S.G. #54b; £28,000). (Image)