this topic pops up every so often, and there's only one source that has proven itself over and over, and that is Genesee Paint in Utica, NY. I'm not related or know these guys, but their work is awesome.
Heres one that they did for me recently matching Lionel's NYC passenger gray from their PA. The top of the pilot has dabs of paint on it!
Heres what they've done for LaidOffSick's 3rd Rail F7... Check out the before and after of the pilot versus the buffer / anticlimber.
Before:
After:
He also touched up around the door frame and filled the holes behind the stainsteel grilles.
They would be more than happy to do this for anyone, just give Gary a call. He matched LOS's F by EYE!
thanks,
Mario.