Here are a couple of MPC repaints done 35 years ago. They were N&W and PC junkers picked up real cheap. The WM short hood was cut off and sliced in half and a new windshield made. Did some F's too.
Used to run a large, 3 track, 072 L shaped thing in my friends basement on the rug. The MPC GP's and F's all run great together so you can run a couple on front and 2 or 3 as pushers on 80-90 car trains and have no problems. Used to have small black rubber bands for any problem couplers.