Don't sell yourself short here Marty, your work on this machine has been excellent.
T2 and Flintstones have great appeal to me, and I'd love to see your T2 when done. Flintstones is a great title, and Wotto's was just a 10/10 machine. Good choice !
GI problems are almost always connectors, or dry joints on the GI connectors on the boards.