When the Met was on tour to Boston and performed, Die Walküre for the first time uncut, not only did Erich Leinsdorf conduct, but the cast consisted of some of the greatest Wagner singers of the time: Lehmann sang Sieglinde, Melchior sang Siegmund, List sang Hunding, and Majorie Lawrence (one year before being struck by polio) sang Brünnhilde. Friedrich Schorr sang Wotan. I’ve only used excerpts, so you won’t hear Wotan or even much of Brünnhilde. This site focuses on Lehmann and that’s who you’ll hear throughout the first act. Only a brief portion of Act II and III is included, because Sieglinde sings only short sections.
You can read what Paul Jackson in his Saturday Afternoons at the Old Met, The Metropolitan Opera Broadcasts, 1931-1950, wrote about this 30 March 1940 broadcast. These are his opinions, but he does state incorrectly that Lehmann began in Hamburg in 1909, when it was actually 1910. He also omits the fact that Lehmann sang the Vienna premier of Arabella.