PCRy 120 was built as Nevada County Narrow GaugeRR 2nd #7. It came from Plymouth with the leading and trailing trucks. NCNG 1st. #7 came without the lead and trailing trailing trucks. At speed hauling a train it had a tendency to hunt from side to side. Even with the lead and trailing truck 2nd #7 still had a tendency to hunt. One other big problem was the high consumption of gasoline. The steam locomotives could haul a larger train over the line for less fuel cost.. I knew John Nolan who was an engineer and master mechanic for NCNG who told me about the Plymouths. First #7 was sold to Madera Sugar Co. as #7. It was later sold to a gravel co. at Friant, CA and later standard gauged. 2nd 7 was later owned by several owners and ended up on Pacific Coast Ry. It still had the lead and trailer trucks. It disappeared during WWII. I have to thank the late John Nolan for the many things I learned from about narrow gauge railroading and steam locomotives.