WTB/WTTF: 4" Trackball? (or Missile Command cab?) [US-WA]

[superlime]

My mame cabinet project is currently living in my office at work, and my boss mentioned being absolutely obsessed about Missile Command.  Any chance someone has a 4" Trackball from a missile command unit they'd be willing to get rid of?  An entire control panel would be awesome too, but I'm trying to keep costs down.    4" trackballs from other systems would probably work, and smaller ones if the price was right.  I'm perfectly happy doing a mouse hack for the optical interface, so doesn't need to come with anything to hook it up to the computer.  I probably wouldn't turn it away as part of a trade deal though.  Would probably be interested in an entire working cab.

Up for trade:
Jamma SnowBros PCB
Jamma TumblePop PCB
Console stuff: http://superlime.com/games.txt
Burly EEPROM burner (worth a grand or so.. inquire if interested)
Random LCDs (pulled from WinCE prototype machines.. most have a touchpad + power inverter)
Random SMT parts (resistors, caps, random usb controllers, ram, connectors, etc)
Random older USB dev kits
Rackmount P3 servers
Tons of P3 motherboards/procs (500-800ish mhz)

I have boxes and boxes of random computer stuff, mostly olderish.  If there's anything wierd you're looking for I might have it.  Just ask. 

Thanks in advance,
-superlime