1) Main module seems a bit darker than other meshes (diffuse\ambient setting?).
2) rear small black window has some gaps (not itself, but between module's main mesh and window), just because normals are "to inside" maybe to copy it and revert normals (doublesided)? maybe not important though
3) I sent textures
4) (middle circular ring around main module has a bit skewed mapping on top)
In the drawing the rings are closer to the sides.
Looks that way here also.
But if I raise it the round elbem are too high?
So not sure what to do. I enlarged the main module by 1.13 and it fits good. But to match the image fully. It is not. It looks like the top of the tunnel is even with the top edge of the wall. But mine isn't. I assume the opening is in the center of the main module. If not then the tunnel top could match the top edge.