Most all of my G scale trains are on shelves by train. Some O scale cars and engines are on my platform ready to be run around my loop. The rest of my O scale stuff is still in their box and stored under the platform.
When and if I ever get a layout up I would like to have all rolling stock and engines on the layout in their respective yards, either freight, passenger or engine facility. And I will probably keep everything together by train so I can couple up the engine and run.
Rick
