Updated 8/13/2018:
We installed the final backdrops on the long wall of the train room.
For the Ohio River backdrop (2 pieces - 1 top & 1 bottom) we needed a level line higher than the 50" bench work height marker. That's why the laser level (on the tripod) is sitting on a table.
This photo show both the top and bottom of the Ohio River panel in place.
Here's the West Virginia side (panels 4A & 4B).
Finally, the troublesome panel 4C was installed and then trimmed to fit the space. That worked!
The divider between the Staging Area and remainder of the layout was spackled and sanded. We will install those 2 backdrops tomorrow or after some bench work is completed.
More when I know it.
George