PL.9 (AF BF)(SPEC C6)/MISSING IMPRIMATUR LETTERING ON COVER. 1855 Health Questionnaire Cheltenham to London with a very fine vertical pair die 2 1d pl.9 L.C.14 (Spec C6) lettered AF BF tied neat 'CHELTENHAM/177' sideways duplexes OC 8 1855 Code F. Important item as AF MISSING IMPRIMATUR LETTERING whilst BF still present on sheet. (Ref 105911).