This unit has several major problems that need fixing. 1: three broken screw posts, nothing that can't be fixed with some glue. 2: the drive eject belt is distorted from years of non use. How do I fix/ where to replace 3: The spindle clamping magnet has turned to dust where can I get this?
For broken screw posts or stripped threading I strongly suggest you try "Surehold Plastic Surgery" glue. It's packaged similar to superglue and can be found in your local Ace Hardware store in the superglue aisle. It's formulated to melt plastic as it bonds and it's not as brittle as superglue. It's wonderful for gluing plastic that normal superglue typically would not bond to.
I'll look into that, I found a fix for the belt but that magnet is the big problem. I can't even measure the thickness of it or take a photo of it because there is nothing left of it except for dust. Here are a bunch of amateurs discussing the problem, i guess they don't know what a magnet is. http://www.bordersdown.net/threads/14691-Panasonic-Q-Gamecube-damages-gamecube-discs
Magnets can be difficult to understand http://knowyourmeme.com/memes/fucking-magnets-how-do-they-work edit: looking at the pics in this thread: http://www.assemblergames.com/forums/showthread.php?33711-Need-Panasonic-Q-Drive-Parts It looks like it has some pretty standard pc DVD drive parts. You could pick up a Panasonic drive from around the same time and see if the magnet from it fits. Just a theory though but here is one for $13 from around the same time frame: http://www.ebay.com/itm/290980466167