Great Britain 1918 2s6d olive-brown "Seahorses", SG413a var.
A superb unmounted mint, with full original gum, right hand horizontal marginal pair printed by Bradbury Wilkinson and overprinted "Cancelled" type 33.
Very rarely seen so fine.
GB Specialised Catalogue No: N65(1)zd.
SG Catalogue Value: £3,000+.