Jeff,
I just noticed we drive the same car.
There were some very good posts on speedometer/odometer repair a couple months ago. Do a search. Your odometer problem might be a gear in the speedometer and there is a place you can buy them. I can't remember the details. But it seemed a couple people had issues at the same time so there were various posts flying around. Someone even replaced their odometer but rolled back the mileage on the new one to match the original. He had video of how to set the whole thing up.
Good luck and after looking at a few posts let me know if you have any questions.
Steve