Okay. Got it figured out. It appears at some point in this distributor's history it had gotten some moisture/water in it, and as a result, once it heated up it created issues with the control module and the rotor. Rotor plastic had a crack in it as well. Not sure that was really causing any issue as it was pretty minor. Pics of old compromised parts attached. If you look at the contact on the rotor the color indicates an issue. Both parts have been replaced and early test drives show much better performance, strong acceleration north of 50 mph and smoother general acceleration and idling. Before parts were replaced, once warm it had a little "shake" during idle and that is now gone as well. If this issue comes back I will report it, but I think we figured it out. Thanks again for all your input.