Reviving this old thread to show my new score. I've had a 6300 in the past, but a friend really wanted it, so I sold it to him with the thought if I ran into another for a good price, I'll grab it.
This guy was listed for free and had a bad monitor. With Ken Layton's repair guide on the monitor, I had it running within the hour. Still needs some love like a good wipedown, rejuvenate the tube, and finish replacing the cheap fluorescent light assemblies with a more original built in style for this model. This is the 6300-T version. I've seen very few examples. Not sure if it's "rare", but definitely interesting when most are the regular type with the smaller monitor on the panel.
These dart games are pretty fun, especially when you can grab one pretty cheap if you're patient.