Updated 10/6/2017:
With my wife's help, I managed to get all the train shelving (Glenn Snyder Display System) on the far wall installed.
The shelves are 9' across (6' + 3') and anchored to studs. The lowest shelf starts at 59" above the floor, giving me the option to raise the layout height to 53" if I so desire (I don't). It will stay at 50". At least that's what I think right now.
I like them!
George