The "great" model railroaders are well known for some of us, though it seems in this instant age of information technology, their names don't appear or are referenced as much as they used to be. For my amateur study of our hobby, Frank Ellison and John Armstrong stand out as greats in O-scale, while HO scale has many others like John Allen and George Sellios.
There was another "great" IMO, whose name may be familiar - Harry Roberts. His layout and wonderful mechanical (genius) accessories were featured in OGR Run 118, the August 1991 issue. Harry passed away many years ago, and I don't know if he ever finished his layout. Like some other talented people, he may have digressed in building custom accessories for other model railroaders. I recall the ads in those older train magazines of his amazing operating accessories, all metal - likely brass - as I recall. Lift bridges, operating coal tipples, coal breakers, rotary coal dumps, transfer tables.
What stands out to be to this day, and what's described in Run 118, is the operating coal breaker (large structure) whereby coal was unloaded into hoppers, where they were then pulled to various stations around the layout, e.g., a power plant with rotary coal dump. I can only imagine the mechanical skills required to design and then build this stuff. Lionel has come out with some of these accessories for 3-railers, but as shown in Run 118, Harry's items were the stuff of dreams.