Sudan 1906-11 1m brown and carmine Army Service, error, SGA6b800. 00 Sudan 1906 11 1m brown and carmine Army Service, type A3 overprint (12mm space), error OVERPRINT INVERTED, left marginal, SGA6b. A very fine positional used example with part "(HAL)FA" circular date stamp showing year "1906". Choice quality and rare. Only 60 originally existed yet it remains lowly priced in the Stanley Gibbons catalogue. The Camel Postman stamps of Sudan are considered by the famous printers De La Rue as the most satisfactory