I have just posted the Blumlein broadcast (The Archive Hour, Radio 4, last Saturday) as 192k stereo MP3. The file size is 78 MB.
I think the sound should be acceptable and quite vivid in places.
There is some stereo information in the Beecham.
Symposium issed four 78rpm sides of the Beecham on vinyl 78s a few years ago. They thought there was little or no stereo information on these discs.
I copied the broadcast from the hard disc of my standalone recorder to DVD. I then played the disc on my computer using Nero and recorded the sound to 16 bit stereo wave using Total Recorder. I used Goldwave to convert the sound to 192k MP3.
The statistics in Nero said the audio was 256k Dolby digital.
I think the standard for the disc is MPEG 2. I think that Nero would have recorded the program in MPEG 2 if I had let it. But a number of downloaders would have been confused.