Okay you've looked here and no luck. So where do you go now? Let me recommend Vintagegamestore.com.
Owned by Charlie Morgan this is one of the best sites for vintage games and parts. Charlie is great to deal with and his prices are reasonable.
Charlie has been on the web now for about as long as we have at gamepart.com. Originally his site was Gameparts.org but he added another site and combined the two.
Charlie is a member of many of the game web rings and knows a ton of folks.
Visit Charlie's site here