British Guiana 1876 Ship Issue Master Die Proof, Rare

1876 MASTER DIE PROOF for the Ships definitive issue inscribed "Postage". Complete design (with blank value tablet) taken in black on glazed card dated "DEC 15 1875". A rare proof.
Duplicate proof to that sold as Lot 1197 in the "Foxley" collection, Spink, London, July 2014.