The B&O was the only road to own this model. They had only 20 units, #7600-7619.
I did my Athearn SD40-2 from an undecorated kit. Although nearly perfect, there are still some changes to be made. The shell attaches to the frame with pegs that fit into holes on the shell. It is very unprotypical looking. Shave off the pegs and holes from the shell. The 3 chime horn included in the kit can be saved for another project. Chessie's SD40-2's came with 5 Chime Leslie horns. Replace the kit horn with a Details West 5 Chime Leslie horn. The kit also does not include a bell. Drill a hole on the side of the long hood and put in a Details West side mounted bell. The kit comes with cast grab irons, really just little ridges of plastic that are supposed to be grab irons. Replace these with wire grabs. The kit also comes without a Chessie rock pilot on the front or a good rear plow. Use the Details West Chessie rock pilot for the front and Details West #130 rear plow for the back. Add Details West unocupling levers, fan grab iron, mu hoses and windshield wipers too. None of these parts are included in the kit.
Below is a pic of a real SD40-2.
Below are finished pics of my SD40-2.
To see more look on my 7619cs-b&o
page or my Athearn
SD40-2 tips page.
((I am working on this project now))