Here is Peter Phillips' answer to my email.

Dear Randolph,  What a story!  It gets better too.  I also need
a photo of Herbert Clair, and you've not only sent me a Rybner, but
Clair as well.  Many, many thanks.  I was also sent a photo by another
MMDer of Rybner at an old age, which I've attached for you.

I am a total Rybner fan!  I have, in e-roll form, all of his Ampico
rolls except Liebestod, unfortunately.  I am producing a CD I recorded
in Vienna, in which my e-rolls were played by a Boesendorfer Imperial
piano fitted with Boesendorfer's hi-end computerised player system.
The results have been highly successful, and many of my friends around
the world are quite excited.  I hope to release all 13 CDs in a few
more months, one of which is called Wagner-Liszt and which features
Rybner.

Rybner's Ampico rolls (excluding Liebestod) are:

  Magic Fire Scene. "The Valkyrie", (59963), 1921
  Siegmund's Love Song "The Valkyrie", (60153), 1921
  Wotan's Farewell, (59943), 1921
  Mastersingers Paraphrase, (58857), 1921/2
  Lucia di Lammermoor (Fantasie Dramatique), (59303), 1921/3

He also recorded his Wagner transcriptions for Welte, but I have not
heard any of these.  I assume the arrangements are the same.  I agree
with you about these arrangements, they are sumptuous and original.
I'm a Wagner nut (even went to the Wagner Festival in Bayreuth), and
I think Rybner's treatment is the best of all.  He is a wonderful
pianist as well.  The Boesendorfer Imperial is also an excellent
instrument for these transcriptions, with its huge bass.

Again, many thanks for the photos.

Best wishes,
Peter Phillips