I assembled the plant's main walls and windows. It came together nicely; I weathered the "old" section (on the left) with some washes of very thin black. The new section had a wash of Kristal Klear (PVA) so it has a bit of sheen. I'm going to try preserve this sheen as it seems the brick has it in prototype pics.

I think if I did it over I would print out templates on paper for the brick sections with windows and lay them over the brick sheet, then cut out the windows--instead of piecing together sections. As it is, it's ok, I'm not going to worry about it. The sandwich brick/3D printed brick sections were fine-tuned for fit with a bit of 320 grit sandpaper, then I used PVA to assemble the sections into the wall. Any major gaps were filled with PVA/Kristal Klear and painted with the concrete grey once dry. Even so I tried to get the fit as perfect as possible.
It really helped to have some test sections to experiment with painting and weathering.
The window glass in the big windows in the old section are not installed yet, and I will be adding patches as are commonly seen on these old factory windows. A piece of 0.20 clear is attached behind the windows with PVA, then little dabs of paint or small squares of paper (the blue and white are paper) applied to the back. I like the effect seen on this test section.

There's still a lot to do, the paved lot/driveway to the loading dock needs to be added, the truck dock and dust filter system painted/installed, and plenty of small details like lights and roof vents/AC etc. Also an interior wall where the rail siding goes into building. But overall I'm happy with how this project is turning out. It's been more complex than I anticipated it would be. But the effect of even the compressed building captures the essence of the Zumbiel plant. There will be a small PRR dwarf signal protecting the main at the switch in front of the building. That'll be a fun project.
