James, I think everyone here is very interested in the "adventure" you are involved with. No-one has vilified you at all, on the contrary, there were dozens of suggestions meant to assist in diagnosing the problem.
I think when you spend 2 grand for something, you should get it, however I also think that when dealing with a very old car and very old components and an equally "experienced" seller, as much as you would like, there are bound to be hiccups along the way...that's just the nature of old cars and older folks sometimes.
On the bright side...and there's always a bright side, you will be a virtual expert on these units and will be able to diagnose and treat just about every ill they would have.
I know that every one of us on the forum would be dropping by to lend a hand in person if it was possible.
We are all rooting for you to find the solution and get back to driving that great old DeSoto
Pat