This is a subject that has come up in the Mechanical Musical Digest in the past. www.mmdigest.com
There is a company, www.zenphdownloads.com
that has invented software that will allow them to take ANY mono or stereo solo piano recording and convert it into a midi file, to then be played on a Yamaha Disklavier Pro, which is then recorded onto a high quality CD This is truly amazing stuff. Take a listen on their website to a 1926 recording of Alfred Cortort that they have converted. The only problem is that they are at this time, only dealing with the vast archives of solo piano recordings from the major record lables for audio only CD recordings. Can you imagine if they could release these in a midi file format to play on our solenoid based players?? I have emailed them asking about just this scenario. They wrote back saying there are several issues that they would have to resolve before they could do that, such as copyrights, playback quality, price etc. I think if enough people email them with this type of request, it may help.
Even so, to be able to hear the great pianists of long ago reproduced as if they were alive today, is incredible.