I've got a gorf, and the real measure of it's value is it's control panel. The things were screen-printed on the bare metal and it is very rare to find one with the graphics in tact. Without a complete panel, it is worth about as much as anly average "classics" cab, maybe a little more due to the joystick. If by some miracle you can find a complete panel, it is nearly priceless.
You can buy an entire rank light assembly for under 50 bucks btw, so having a working one doesn't really add that much to the value.
Kangaroo, as the others have stated, is pretty worthless, all the restoration in the world can't save a bad game.
