I am intrigued that the model has been deemed printable by Shapeways, or anyone else for that matter. Scaling it down by 3 decimal points means that the wall thickness is 1mm, with the panel side trim barely discernible. The copy / minus scale issue is evident on the side trim also, so best to just copy, rotate and paste the good one. Same with the roof panel. There are several overlapping and intersecting parts that could create problems in actual printing. Assuming that it will be printed in resin (as the approach would be totally different - and probably not a success with fdm), I would thicken the walls, fix the panel side trim, make sure every component is manifold, and make it all one group with Outer Shell. If it is to be done by fdm, I would break it down and print it in separate panels, and then assemble it.