More Weight Reduction

It turns out that I have a total of six bolts holding the bottom plate of the mirror cell to the attachment brackets -- and the bolt, lock washer, and nut combo weighs 0.4 ounces.  Strictly speaking, six bolts are not required.  Each one has the tensile strength to easily hold this, and I am not worried about any of them working loose.  In addition, I can also remove the extra material on the attachment bracket where the second hole was located, perhaps saving two ounces total.

UPDATE: When I was looking for an alternative to turning down the bottom plate of the mirror cell, I did a little thinking about alternative strategies.  One is to cut the circle to a hexagon, which can be done by drawing a circle of the required diameter, measuring 60 degree angles, then drawing lines connecting the points, and running these through a bandsaw.  In addition, the area of a hexagon that fills radius r is 3r², instead of pi * r², so slightly less weight. A triangle is another possible strategy, where the area of radius r is 2r², so even more weight reduction.