I have a Williams System 6 board set from a Blackout for sale. The owner of the game had me switch it out with a new Rottendog board set.
The game worked but I think it had an issue with the switch matrix. Sorry, it's been a while since I worked on this one and I don't have a way to test it.
I'm asking $150 OBO plus shipping.
PM me if your interested.
-Dave