Knocked out a bunch of little stuff today. Drilled the sub panel lower angle for mounting control cables. Then match drilled the instrument panel lower mounting angles by clamping them in place, then drilling them to the panel and holding the panel in place longitudinally with some wood blocks clamped to the side rails. for reference, the correct location worked out to be 5" from the aft face of the panel to the seam between the two sections of side rail.

Then I match drilled all skin to substructure holes full size.

Before removing the skin to finish drilling the panel angles, I went ahead and installed the optional fwd access panel kit. I had ordered this a while back and was on the fence about whether it was worth it to actually install it. It brings up the possibility of water intrusion if it isn't sealed up right afterward, and i've seen some on completed airplanes that were bowed between mounting screws or didn't fit right because the holes were kind of a hack job.

After thinking about it a while, i decided that the access they afford during initial install was worth the potential downside, and if I was careful, I though that I could probably get a good result.

I just followed the kit instructions for the layout, cut the initial hole with an air nibbler, and then crept up on the cut line with a sanding drum in a dotco, then finished it by hand with a 1/2 round vixen file. It took about two hours to cut the holes and finish them to the tight tolerance I was shooting for, but the result was really nice.

I'm thinking about fabricating a .025 spacer to sandwich in there so the mounting ring will set a little lower and allow an extra .025 for a gasket formed out of pro seal (used per plan) or RTV. I'm thinking that not having enough gap in there is what causes the pooched appearance I'm trying to avoid, due to people cranking down on the screws and causing them to bow up between teh screws due to not having any room for sealer in there. I'm going to sleep on that idea and come back to this. As well as remove the skin and finish match drilling the lower angles.