JHZ, thanks for getting us rolling once again. How old is Socks now? I seem to remember a picture as a puppy.
Mel, the B&M had some handsome paint schemes.
Peter, I'm staring at a blue Conrail EF4 numbered 4606 just like the one in the picture made by Williams. Would the one in the picture also be a Williams product? If so is the 4605 PC also Williams?
Edit. Peter upon enlarging your photo to confirm the number on the PC EF4 I noted the detailed handrails so I know they are not Williams. I guess the EF4s must be numbered to match prototypes.