Korg DW8000, Mono/Poly, MS-20...

Hey all,

I managed to pick up a DW-8000 recently off of eBay for the astounding
amount of $51.00.  Yea, I got a deal...   Problem is that, and I knew
this buying it, the owner had previously sold it and the shipper
damaged the keyboard.  Destroying the joystick, and slightly crunching
the back right corner.  Other that that everything works fine.  I
would like to try to replace the joystick though and that is my
question,  Where can I get a replacement part or, if I have to,
rebuild and replace the joystick with something fabricated.  

Thanks