By the way, as a recent purchaser of both the Dell AT 101W and a vintage SGI AT-101, I was surprised at the difference in the quality of construction of these boards. While the Dell is nice, and certainly far more solid than current Dell boards, the SGI is far heavier and far more sturdily built. The key action is not as clicky as the Dell but far smoother and more solid.
It's pretty clear that Dell licensed the design from SGI (the boards are visually identical except for the color) and proceeded to cut corners right and left.
The "granite" case of the SGI is a bit strange (it's supposed to look like actual granite, with little specks in the plastic), but, on the other hand, it certainly won't show fingerprints and cookie crumbs. Pretty crafty.