J6 (D6) 1934 Underfranked Air Mail cover from Great Britain to Kenya, 1d and 6d Great Britain stamps tied by Portsmouth cds, charged 1' Postage Due with boxed "T." handstamp, bearing the all but impossible 1' grey-green of the first Postage Due issue tied by "Daressalaam" cds, from the celebrated Pennycuick collection.