These are two cards that were probably in a folder given to each passenger as they boarded the plane. You added your message to and address of your BFF back home, give it to the stewardess. She would then affix a stamp and mail it for you.
They are DC-3 aircraft in NWA livery (at one time, pretty much any airport worth its tarmac had a DC-3 landing there). Later, NWA became Northwest Orient, flying to Japan and other points oriental. “Northwest Orient” makes me think of elk and soy sauce…
NWA was around from the late 20s, then was absorbed, eventually, by Delta.
Uncle Bob's Pix 