British Empire - Day 6

1861 Woodblock 4d carmine on laid paper error of colour, used with cancellation leaving "FOUR" clear, small to good margins except fractionally shaved at top right, repaired tear at top and central pinhole, still among the finest of the 15 known (of which probably only one is in sound condition) and unknown in unused condition, one of the rarest and most iconic stamps of world philately; cert. Richter (1990), Eichele (2010) and RPS (2016) (S.G. £95'000, Mi. €130'000).