To get the lights back in sinc, turn off power to the track for 15 to 30 minutes or remove units from powered track for that long and it will reset the electronic units.
Also these cars are made before Lionel took over K-Line and NO parts are available from Lionel. You may get lucky and find some parts from a K-Line dealer who has some left over.
I have the 18 inch Reading Company interurbans from about 12 years ago, bought a K-Line heavyweight passenger car to go in the center and painted it a shade of Reading green, so far no lettering on it. I have had to replace both truck assemblies on the heavyweight car as they fell apart in my hands, K-Line told me to mail the trucks to them and they would replace them free and so I did, replacement trucks have held up!
Lee F.