unconventionally countersigned by C.O., addressed to Ross, England and bearing 9p. tied by squared-circle d.s. (KD19). A rare concessionary rate cover. Photo" /> cover 1892 (Apr.) Seaman's letter envelope (tear at foot) <I>"From G. Stevens S.B.S. H.M.S. Oyne Aden"</I> unconventionally countersigned by C.O., addressed to Ross, England and bearing 9p. tied by squared-circle d.s. (KD19). A rare concessionary rate cover. Photo | Christie's