Thanks everyone for valuable feeedback - really appreciated. I might reach out to MoparMike, depending on shipping costs... or simply shell out for a new board I think... Has anyone had positive experience with new boards from CI?
My 70 Duster has the rallye dash so it has 2 circuit boards. I bought both boards on EBay from a seller named "fmmpar". The price was much less than CI and they worked great!
Edit: I see he does not offer one for your Dart, but Classic looks to have one if you want to go that way.