Vintage Synth Repair

Hello all. I have a Kurzeil Mark 10 with three different midi options 
and a flopy drive. I'm sure that there's something available to plug 
in, or stick in the drive to make the Hammond sound from this 
keyboard. However, up to now my efforts have fruitless. Also, my 
Hammond C-2, has a dead note. The lower A note on the bottom keyboard 
is dead. I sometimes use for the bass  that seems to complete the 
effect that I want. Anyone know how to fix this and care to share 
that information with me? Thanks.......... Mark, from Missouri..