The rarest (and oldest) game I own is Williams Yukon from 1971, with 730 made and apparently not many left. It was at TPF 2016 in the VECTOR section. What makes ours even rarer is our special "solid-state augmentation kit" which at the time included motion-sensitive LEDs around the backbox, not to mention tons of additional new wiring throughout the cabinet. I'll have to share more on that when it's done!