If you are looking for the original music to some of your piano rolls
or if you are looking for something neat you can't find on roll, or
something you can convert into a MIDI file for your E-roll to play,
check out the Charles Templeton Collection of Ragtime Era Music, now
digitized and available on the net complete with cover art.  This is
also the way to find the original words to go with your MIDI files
which do not store the words on word rolls.

The collection includes blues, show tunes, music from minstrel shows,
Irving Berlin, war songs -- basically everything you probably would have
in a good piano roll collection: http://library.msstate.edu/ragtime/

D.L. Bullock
http://www.pianoworld.us/