The Delaware and Hudson had ALCO build them the L.F. Loree, named after the D&H president, in 1933. It was a four cylinder non-articulated Mallet 4-8-0 with higher pressure cylinders under the cab and low pressure ones up front, plus tender booster truck. All drive rods, from front and rear cylinders went to the second set of drivers. It was a very efficient steamer, but not enough to compete with diesels. Those two steam coaches pictured above, somewhat similar to some inspection engines, and to the photo at Shelburne, are what I want to build/kitbash. I have not even heard of a model of one in HO. (nor of the L.F. Loree)