Adding to Tom's reply: The daytime B&M-CP "Alouette", which operated via Woodsville, NH until 1954 used pooled power - B&M E-7s and CP E-8s. B&M "American Flyer" coaches were common. When the Woodsville - Plymouth line was abandoned, the train was rerouted via While River Junction and converted to RDCs, also pooled between B&M and CP equipment. The overnight "Redwing", which operated via White River Jct until 1959 seemed to feature only CP sleepers in the streamline era, but coaches came from both roads.
Dave
Dave