Lot 30202 – 1940 Undercover registered mail from CASOC (later ARAMCO)

1940 Undercover registered mail from CASOC (later ARAMCO) in Dhahran via Bahrain to the US Legation in Baghdad for onward transmission via military mail (APO 578 in Basra). The earliest of 7 known registered letters sent thus between the bombing of Dhahran by Italian planes (October 1940) and the Saudi-US agreement for Casoc to use APO services (May 1943). Franked with Bahrain 1A (3), 4 A (15) and 5 RS., a very rare stamp on cover