Well today I decide to reduce the left hand side of the building that goes through the access hole down to one set of modular pieces.
I also added another set to the right hand side as Rich recommended. I'm very happy with the way the building not only looks now, but also operates as far as spotting cars goes. I can get one car into the far left side without it fouling the turnout.
I also re-adjusted the brickwork and configuration of the modules to suit the final design and placement of the pipe gantry the will enter the building and hide the plaster seam.
The right hand side has had one more set of modules added to the far right and the top.
Shot showing the clearance from the spotted car to a car traversing across the turnout, although tight it fits.
Now all that is left is to add the final parapets to the modules, add the returns back to the backdrop, add the roof sections and choose a brick colour.