austin_dern pointed me to some very early Disney radio shows:
https://archive.org/details/mickey-mouse-theater-of-the-air-1938-05-15-20-old-macdonald/Mickey+Mouse+Theater+of+the+Air+1938-01-02+(1)+Robin+Hood.mp3 Most of us are used to hearing the voice of Walt in his final decade of life, so here's a chance to hear his much younger voice. (Plus many of the standard characters of the 1930s era)