I'm looking for decent-quality audio of the following old radio programs. Any leads most 

"Open Letter on Race Hatred" - CBS, summer 1943, with ending statement by Wendell Willkie

"An American In England" radio series produced by Edward R. Murrow, written and directed by Norman 
Corwin, done at the BBC in England. The first show was broadcast live, subsequent shows were 
recorded and broadcast by transcription.

"This Is War" radio series, circa 1942, multiple networks

"An American In Russia" series, CBS 1943

"The Challenge of the 50's - Years of Crisis", CBS 12/30/50

Thanks in advance for any tips/leads.

-- Tom Fine