Dave, I'm glad that was helpful. It got to where I just had to raise the outer loop, with the height of the shelf and the small dimensions of the room it was too hard to see all the trains.
The signs and passenger platform in the corners are raised on stacked pieces of 2" foam.
I learned a lot from this project, there were some challenges that I did not foresee. First, it was very difficult to get a good level line all the way around the room. I used a Black & Decker Bullseye laser level, starting at one corner and going in both directions. After several tries the lines still missed each other by 1/2" at the far corner, so I had to average the gap and go from there. I'm sure that a professional laser level would yield much better results. Also, after mounting all the brackets directly to the wall I found out just how un-plumb and uneven my walls were. To eliminate unsightly gaps I ended up caulking around every single bracket, and along the underside of the shelf all the way around the room, then touching up the wall color. If I ever do this again I think I would mount the brackets to a series of backboards, then mount those assemblies to the wall; it would be easier to caulk a single straight edge. Although, I do think I prefer the appearance of the brackets mounted directly to the wall.
To make the ends of the shelf sections mate up, I used a plate joiner to cut slots in the ends, and installed biscuits. The shelves fit so tightly against the walls that I did not need to use any glue.
Ryan that is really cool that your wife wants to run Standard Gauge! I'm hoping that one day my wife will want a train of her own. For now she tolerates my enthusiasm for toy trains, no doubt because it keeps me off the streets!
Good luck,
Mark