Dave, I have been in your position, maybe a little bit worse. As I live in the UK with only one Lionel dealer for the entire country. They don't really repair the modern stuff.
So out of necessity I have had to fix my own stuff. Thanks to lots of patience and advice from the likes of Jon Z at Lionel and Gunrunner John and others on the the forum I have managed to fix everything (so far...).
So I'd be inclined to try and fix it or see if Guns or one of the other tech guys on the forum would take on the repair?
Nick