I grew up in the bay area and frequented RC many times until we moved away in 1985. I was ‘lucky’ to experience a trip up the mountain with the kahuku/OC1 double header with the #40 diesel pushing from behind. It was a slow trip up and the train was separated at the switch back (a la Monarch Pass style) with the two steamers taking most of the train up the reverse portion and the diesel handling 2 or 3 cars separately. I’ll say it was ridiculously cool to see this (I would have been 8 or 9 years old). I still remember the way those engines sounded as a they worked in tandem to get that train up the hill. The pics I took are long gone.