While hunting around for more vintage audio, I came across a link to vintage video which lead to more vintage audio. I found these and thought some of you may be able to use them. There's also contact information to groups which may possibly lead to more files.
I have found a set of Orson Wells' radio shows dating from 1941 through 1945. They're available as mp3s and .ogg vorbis. The files numbered by the date - eg 411207, as well as a description of what they pertain to.
http://www.archive.org/details/Orson...timeBroadcasts
There's also a series of files for The Pacific Story which was on NBC radio, at 11:30pm (EST?) from July '1943 until 1947.
http://www.archive.org/details/OTRR_..._Pacific_Story
http://www.archive.org/details/OTRR_..._Story_Singles
The quality of he files that I have heard are very good. Adapting them to the game, I leave up to you as well as whether or not to use them at all.
I will report on more materials as I find them.
Cheers..