I have a quickie update. I had to step away from the S-type project for a moment today as it seems to be fighting me on getting it completed. I grabbed a battery and a fire extinguisher to see what I could learn about my mysterious car. I got a pleasant surprise in seeing the dash actually Working! The little screen showed several (expected) issues and seemed to be ready to work. Odometer shows 24500 miles. Having that much working tells me that the mouse damage under the hood is likely limited to that area a good sign as well.