on 2d. bright blue, unused with small part original gum (slightly disturbed), centred to upper left, fine. S.G. 15, £700. Photo" /> unused 1875<I> "One/Penny."</I> on 2d. bright blue, unused with small part original gum (slightly disturbed), centred to upper left, fine. S.G. 15, £700. Photo | Christie's