Rare First Flight cover!

1969 – First flight Jamaica – Baltimore
First flight Eastern Airlines Montego Bay, Jamaica to Baltimore, Md. Flown 13 Dec 1969 – Arrived next day (PM backside). Eastern Airlines Airmail cachet, “Par Avion”. Jamaica SA stamps of 1965 commemorating the centenary of the international SA. Remark: Very rare item – only 52 pieces flown. Estimated value: £50 +