Below is a Dean Heacock pic of two real double doors.

To get these cars completely accurate would require removing
the walkways and filling the holes. I didn't want to do that with
mine. Also you will need to make the two doors different sizes like
the pics above. I left mine as is.
Mine came undecorated and I painted and decaled them
myself. I am uncertain as to which schemes, if any, Athearn puts
out for Chessie, B&O, C&O, or WM.