Shelf Layout?

@mejo2 - What scale are your rolling stock? If HO then a 12" shelf may be adequate for display. A lot can be done with a nice photo backdrop and just row modeled.

A Midwestern theme might simply have a raised roadbed with drainage ditches and some grasses. A barb wire fence separating a foreground of fields of wheat or pasture would be enough.

Mountain scene could allow construction of a bridge or two, maybe a snow shed and tunnels. A small station with a team track or spur would be an easy way to show off equipment and give you some construction projects.

I don't know much about Appalachia but others here may be able to give you some ideas.

HO

HO is the scale. I am also contemplating a switch to N.

" a diorama to showcase

The most convincing scene would be a yard (where multiple car types would realistically be present). Make it a few tracks wide with dirty ballast and other typical yard details then add a nice photo backdrop of yard type background scenery. Here's a test shot I did for my N scale layout, it's just a snapshot propped up against the wall with some flextrack on the table but it shows the potential...DaveB