So I figured that not many people would look at the other thread, so I started a new one. Is this recording possibly Laurette Taylor? Around the 4 minute mark there is a clip of audio from the show right after describing Laurette Taylor. Is this her in it? Whoever it is, she gives a beautiful performance.
I love that documentary though I prefer Orpheus of the Stage.
Anyway it sounds like modern actors to me--the fidelity is too high. There is that rumoured radio clip or whatever that has been discussed on here before, but...