NIGER COAST 1894 '½' on left half of 1d vermilion, SG63Niger Coast 1894 (Aug Sept) '' on left half of 1d vermilion, type 15 surcharge in VIOLET, Opobo bisect provisional, tied to piece by 'OPOBO RIVER' circular date stamp, dated 'SP 19 94', SG63. An exceptional used top marginal example WITH PART SHEET NUMBER IN BLUE CRAYON (apparently '1 3 (?)'). Small surface mark at lower left corner, not mentioned by clear British Philatelic Association certificate of authenticity (2011). A major rarity as only two