Check out this fascinating website devoted to the neglected works of Beethoven.
"Now YOU may judge for yourself as to whether these pieces deserve a wider hearing and the ability to join the repertoire. These never-before-heard works are now available to anyone with a computer, a modem and a soundcard, in the form of MIDI files. Our rule of thumb has been that if a work has been recorded and is readily available, we will not produce a MIDI file, concentrating instead on the works which are not otherwise available. At present, over twelve hours of Beethoven's music is available on this website and in no other listenable format."
The Unheard Beethoven