Located and pilot drilled both left and right vertical stiffeners.
Spent the most time trying to locate the aft support, SNX-F16-04. This is supposed to be 8.75" from the bottom of the aft tunnel zee to the top of the aft support. I'm consistently off just shy of 1/16" from level. Complicating factors is that the fillet in the aft support angle causes the zee sheet stock to not fit flush. Tried several different ways to clamp the assembly in place and measure the top; each time was a compromise. It's getting late, and I don't want to screw things up worse than they are, so I'm quitting for tonight. I have in mind something that will probably work, but am just tired of trying things right now.
