We only have had 2D drawings of the mirror box's parts, and that prevents most of us from understanding the installation/hanging procedure of mirrors.

After the today's dry-run of the review (internal review) on the procedure, I've reconstructed the 3D data briefly from the 2D drawings, only which the manufacture company provided us (uploaded to the jgwdoc by Tatsumi-san).

If I didn't misunderstand the 2D drawings, the reconstructed 3D model shows a mechanical intereferance between one of the blue pillars and the mirror base (see the third figure attached).

And also, I think the base has a too narrow foot and should be widened!; the rail on the other side (the mirror-hanging jig) should be modified accrodingly.