So far all the pictures I've seen of the diner and baggage were lettered NYC. Pics of the observation mostly seem to be focused on the rear platform so its hard to tell. I know that all of the sleepers would be Pullman
I have a PRR observation from GGD. Im pretty sure it does not have any sleeping compartments. Just coach/lounge seating. Going by seating configuration sounds like a good way to pick the one to order.