I did, sort of. The ribs were cloned, but the rectangles joining them were put in with the rectangle tool. About two minutes after posting that picture, I came across another photo that showed the legs at the lower rear of each rib were wrong. Fortunately because I had made each rib from one component, by opening just one of them and deleting the "leg" it applies it to all of them. This is because components, unlike groups, are identical, and whatever you do to one, automatically and instantly updates the others. The array was made by STC, and I then happened upon some text saying it was approximately 35m wide, so I had to use the scale tool to adjust it after it was built. I'll post another shot shortly showing the updated model.
Got it fixed. One of the problems (I think) with sketchup is when you want to slice through something, and delete one of the slices, it isn't very intuitive. In the pictures above, some of the grass banking was under ground level. After much faffing I worked out how to delete the underground bits. Its recompiled and no more shadows.
Its funny how the boring buildings are the most difficult. The NAD office block was a Bl00dy nightmare. And its the biggest model so far at almost 3MB. There was an extension to it in the late 70's which I haven't included... yet. It was done in brown brick at the same time as the Radar Establishment had their building built and another building adjacent to H1, all in the same style with brown brick. I may add them, I may add them later as a "late 70's" addon, I may not bother. Anyway, here are some of the latest images from the Office building build...