I don't know the answer, sorry, but that Interstate ES44 is really a nice looking engine. There is a Premier version too. I wish you folks would stop posting pictures of them, I have been able to resist so far, but I am growing weaker with each new picture...
I couldn't resist the RS-3 in the Interstate livery, they got me on that one.
Hope someone can answer your question.
Edit after seeing Mr. Muffin's post: Mr. Muffin you are not helping my strength any here. In fact you are accelerating the weakening...