CAMEROON (British), 1915, -1/2p on 5pf Green, Double Surcharge (54a; SG B2b; Gibbs 2e).
Cancelled by "Duala 18.8.15" circular datestamps (bottom strike causing minute pinhole), well-centered, fresh and Very Fine, an enormously rare stamp, while 100 were theoretically printed, Gibbs notes "...I have seen four or five used singles at most, usually in poor condition...",
undervalued as such, with 2005 B.P.B. certificate, SG £1,000
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