There's plenty of scenery and structures to complete. That's about as far as Dave got in completing this. One of the things that doesn't require much thought is the sense that a propane dealer as modeled, albeit well done, is not a transition era thing. At least I don't think it is. Also the metal buildings. Both easy changes but then, what do you replace them with? If a business, what business? I have always liked the idea of a Harley or Indian dealer as motorcycles have been an integral part of my life and it affords a pretty good opportunity for a very cool detailed space. The Harley dealer would be more flexible for era as Indian was defunct by 1957, I think.
I also need to do a station to replace the scratch built one. If I stay with the space originally allocated I will need a footprint around 2 1/4" x 2 5/16" or less. The 2 1/4" depth is a max and would probably be better around 2" for some sidewalk space trackside. It also wouldn't be hard to change the space as it's basically a perimeter set by sidewalks but there really isn't much space to go larger as there just isn't much space beyond the set perimeter.
One thing that I wouldn't mind having would be a coal mine scene but I see that as a pretty major disruption to the existing design and would require careful thought to accomplish it without making a mess and also maintaining some of the division that exists. Or maybe that division wouldn't be necessary.
I haven't yet given much real thought to how that might be incorporated.
Most of these mentioned things could be accomplished incrementally without major disruption to the operation of the layout so there would be no urgency to complete them. The coal mine idea would be much more involved, I think, and satisfying my desires for such a scene may not even be feasible. And I'm OK with that.