1934-36 Photogravure Definitives Full Set

Complete set of eleven 1934-36 George V photogravure definitives on one cover all postmarked with the correct nine first day of issue dates using a mixture of Sutton Coldfield & Birmingham CDS. Leading stamp dealer Francis Field produced about 25 of these extraordinarily rare covers which would have been against GPO regulations, & must have been stressful to produce as just one wrong date would have ruined the whole cover.