Here’s an abbreviated Wikipedia entry:  “WOCB first signed on as an AM station October 2, 1940; the station was originally owned by the Cape Cod Broadcasting Company. It originally operated at 1210 kHz, but moved to 1240 in 1941. WOCB shut down in May 1943 after running out of money, resulting in its license being canceled by the FCC on November 30.”  Basically, it’s now WXTK.  As for the postcard, it’s Tichnor 76250, not postally used but the writer filled the reverse with a message that may have been sent in an envelope.  Grade: 4