1873 GB USED IN PERU ON COVER. Envelope, opened our for display from Callao in Peru to Glasgow Scotland with 1d pale green local issue paying local postage and cancelled PERU date stamp, also GB 6d grey pl.12 (SG125) lettered FA and 1s green pl.7 (SG117) lettered SC tied very fine single strike 'C38' barred numeral of Callao. On reverse CALLAO date stamp AU 27 73 and GLASGOW SP 28 73. Rare usage. (Ref 114312).