I recently purchased a 322 for parts. The locomotive wheels had been changed along with the reverse unit. The tender has all brass wheels and a very small knuckle coupler installed. Does anyone know what this stuff is? It doesn’t run so I can’t tell if the thing replacing the reverse unit does the same thing. Why were the wheels replaced and how could it run with metal wheels on both sides of the tender. I am curious and interested in why these modifications may have been made. Thanks in advance to anyone with knowledge of this stuff.