Great Britain 1937 King George VI 1d. scarlet. IMPERFORATE IMPRIMATUR TETE-BECHE STRIP OF FOUR. Handstamped ‘NP IMPRIMATUR’ on reverse and sent to the National Postal Museum for their archives. Superb unmounted mint condition. KGVI Expertising Certificiate No. 0974/07-08 (2008). (With original Auction card from National Postal Museum sale). EXCEEDINGLY RARE.