These boards are extremely rare. Very expensive even if a working one is found. If you have one that's nonfunctional, you can contact Ed Cheung http://www.edcheung.com/ for repairs. He'll do your board for less than $200. Mail it to him, he'll mail it back within a week. He says he's never been unable to fix a Space Shuttle that was sent to him.

Keep your eye on on eBay otherwise. They show up occasionally, but not less than $300.