What I can only hope it the final chapter. Well, at least for the tender, who knows what the inside of the locomotive looks like!
I went to put it back together after replacing the coupler, fixing the wire, and cleaning up the other wire. Even with taking some meat off the bottom of the RS board holder to lower it's profile, something was still hitting, and the tender frame was rocking and I couldn't seat it. After a few more measurements, it became clear, it's the big capacitor on the RS board, it was running into the PCB for the volume control and lighting. Short of losing the holder totally, there will never be enough clearance. Since the screw that holds the tender on is under there, and it needs clearance, I went with a compromise. I canted the board to one side so the connectors didn't clash, and angled it so the capacitor missed the upper PCB. Now the tender shell goes on without hitting anything.
One wonders how they got any of these together without wrecking something with those clearance issues!
Since I was already in there, I treated my self to a shorter coupler, looks better coupled up to rolling stock. I suspect it might no do tight curves, but I'm not planning those anyway.