J1-6 (D1-6) 1933-34 An exceptional complete set of six first Postage Due issue on four different commercial covers and one postal card, all are ex-the celebrated Pennycuick collection, includes a local cover to Dar-es-salaam bearing 2x 5¢ plus 20¢ Dues, postal card from Amani to Tanga with 10¢ Due, cover from Tanga to Dar-es-salaam tied by 30¢ Due, O.H.M.S. stampless cover from Mwanza to Dar-es-salaam tied with 40¢, underfranked Air Mail cover from Great Britain with the almost unheard of 1' tied by Dar-es-salaam cds, this groups represents an almost impossible achievement!, which must have required many, many years of diligent effort on the part of one of East Africa's legendary philatelists!