MiDI files are supplied for use on a single organ. If the organ for which the file was purchased is transferred to a new owner, then it is acceptable for the MIDI file can be transferred too.
MIDI files must not be copied, resold or otherwise shared. The only exception to this is if a roll (or book) is needed. In such circumstances the file may be temporarily shared with a roll/book punching/cutting service for the sole purpose of converting the file into a single roll/book. Once the roll/book has been made the file should be deleted.