Disklavier

I am trying to convert songs of my deceased mother playing the piano and singing from 1975 into a midi song file that will play on my Disklavier e3 piano. I digitized her songs from cassette tapes into .wav and .mp3 song files. AmazingMidi and Intelliscore have produced unusable midi files that are not even close to the original. Any suggestions would be most appreciated as it is my dream to have my mom playing my piano for me again. Joe