Cover franked with single 1864 6d red brown 'Chalon' issue (SG 122) tied by barred 'OTAGO' cancel in black with fine CLUTHA FERRY OTAGO cds alongside. Addressed to UK with DUNEDIN transit cds on reverse. This P.O. was only open between 1858 and 1865 and the cancel is unrecorded by Wooders. An exceptional rarity.