The problem is the interconnecting piping. I won't be able to reach it to measure and install it when the models are mounted on the layout. It's all facing a wall and the units are in the way. Now that I'm thinking about it, I could have (and maybe still be able to) reverse the plan and have the pipe alley on the front side. The only pipe that would have to go to the back would be the two lines going to the loading rack.
I'm seriously going to think about this. It would mean drilling some new holes, but all the gear would be reachable from the aisle and I could do all the piping in its final position.
That's why I like the give and take of the forum. I would have never had this thought without your suggestion. There's no reason why I have to stick to Plastruct's design with the pipe alley lying between the units and the railroad. I will plan it out while the board is in the shop and then move it into the layout and fasten it all down, and then lay in all the units.
As Gene Wilder so vociferously stated in "Young Frankenstein", "It Could Work!"
