Great Britain 1965 1s6d Salvation Army Centenary (Phospor), SG666pvar.
Superb unmounted mint full original gum left hand marginal imperforate horizontal pair of imprimaturs showing "Extra Pearl" variety in position R.17/1, each stamp with a "BPMA" handstamp on reverse.
A scarce horizontal pair from the very first approved printing sheet.
Exceptional provenance as they were released from the British Postal Museum Archives in 2014. Prior to this they were stored in the museum archives in climate controlled vaults since being printed and are therefore in uncirculated mint condition.
