I've got copies of all but two of his 37 [Ampico] recordings.  I've
read, so it must be true, that they were made with endless care and
re-editing by Edgar Fairchild, and with his contributions through
the editing process.

The [audio] recordings I'd watch out for and avoid are those made
electronically from Ampico recordings and purport to more closely
resemble what Rachmaninoff intended.  These recordings basically take
the responsiveness of the pneumatic Ampico out and replace it with the
electronic readout possible from the paper roll.  Certainly "more
accurate" in one sense, but Rachmaninoff approved what the editor was
able to get an Ampico to do.  Thus the response of the pneumatic Ampico
was factored into the editing done for Rachmaninoff.

So why is it that the last two, 57604-H, Barcarolle Op. 10 No. 3,
G minor, and 60891-H, Etude Tableau, Op. 39, No. 6, have never turned
up in the 10+ years I've been lurking?

Douglas Heckrotte

 [ Seemingly complete lists of his phonograph records and piano rolls
 [ are at https://en.wikipedia.org/wiki/Sergei_Rachmaninoff_Recordings 
 [ -- Robbie