I hate to tell you, but you could have made some GOOD money off of those parts. The last one of those boards I had I sold for $100 untested, and another $125 for the gun.
I think your problem giving it away is your location. Try posting it on RGVAC instead, might get some better interest there. (If you do not know what RGVAC is, it's a usenet group: Rec. Games Video Arcade Collecting)