My father in-law (original owner of my 87 GN) is building a new house and while preparing for the move he found this book. It is the Buick dealers book he picked up while searching for a GN.
It has all the specs, options and ordering information for all models. 98 pages worth and in good condition. I small tear at the top of the binding is all that's wrong.
Anyway, it has some great pictures of the GN, a WE4, and the 3.8 Turbo engine. I just noticed that they highlight the oil pump, calling it the gerotor oil pump. It looks like the kind they use in NASCAR, the 'gear in a gear' design. Now that's something I didn't know :-)
If I had a better scanner I would take some images, but with the one I have now I would have to rip the brochure apart, and that aint gonna happen ;-)