Great Britain 1963 2 ½d Ninth International Lifeboat Conference (Ordinary), SG639var.
Superb unmounted original gum bottom left hand corner marginal 3A, 2B, 1C cylinder block of six imperforate imprimaturs, each stamp with a 'British Postal Museum and Archives' handstamp on reverse. Some light gum disturbance in lower margin from original mounting of the sheet by the Post Office, nevertheless a unique positional piece.
From the very first approved printed sheet of this classic stamp issue, the equivalent to a "first edition", and with the highest possible provenance originating from the British Postal Museum Archives.
