When I moved to Seattle, 15 years ago I sold all my HO train stuff on eBay.
I am 80 now and have walking problems so I decided to try working on trains again.
What I did previouly was to build Roundhouse Old Timers in the image of Narrow Gauge. These are the 36ft trussrod cars and old time steam locomotives.
I wss surprised to find out that Roundhous was long gone but eBay has been my friend. There seems to be a good good supply ot Roundhouse items on eBay. But you need to be ready to repair some of them.
I grew up with the Southern Pacific in the San Francisco area. The Western Pacific was the other railroad. These were in the days of STEAM!