cover 1897 (Jan.) unstamped XU5 to London, marked "Field Service, No stamps available, Merowi Sudan, 19-1-97", showing Wadi Halfa c.d.s. (1.2), boxed "T" with "5D/F.B." (deleted) and "2½D/F.B." handstamps and, on reverse, Cairo transit c.d.s. Photo