I peeled back the forward side skins a few inches on both sides so I could get the right angle drill in place to match drill the F-684 gusset to the existing holes in the auxiliary longeron (the angled one). Then I match drilled the firewall angle to the pre-drilled holes in the gusset.
The 902 bulkheads went in next (the vertical piece in the pic below). Well, they went in and out and back in about 10 times. I had to flute the flanges that go against the skin, which was easy. What took a lot of back and forth was getting the web of each bulkhead parallel with the web on the other side. I think there is some sort of a bracket that attaches the subpanel parts to the bulkheads, so it needs to be in the same plane from side to side. Out of the box, the webs were pointed about 3 inches behind the other side.
Once I had the bulkheads done, I moved on to the 9101 gear attach webs. It's hard to see in the picture below, but it's the shiny piece of sheet (thick sheet - maybe a little over 1/16" or so). These webs sit on the gold 904 bulkhead and nest in the angle of the auxiliary longeron. They also have a flange at the fore end that gets drilled to the bulkheads I just put in. I had to sand a bit of material off of the bottom (top really, bottom in the picture) of both left and right webs so they would fit into the longerons, then I drilled all of the holes based on the existing holes in the skin and longerons. The holes in the middle of the sheet will get enlarged once I pull it back out. They are for fuel and vent line passthroughs/attachments.
I clamped the forward flange of the web to the 902 bulkhead and drilled them together. There is also a tab on the 902 bulkhead (both on the top and bottom) that sits on the longeron and has to be drilled. That was awkward to say the least. The tabs are oddball shapes and only sit partially onto the longeron, so it took a number of marking attempts before I had a drill location that I thought would be okay for both the tab and longeron. As I was drilling the tabs I realized I had never match drilled the big lower longerons to the side skins, so I did that next.
I cut the angle for the left and right 996C reinforcement angles and got the layout figured out. From what I've read online, the locations of the holes shown in the plans are very wrong for this part, so most people suggest making the parts as blanks and match drilling using the skin vs drilling holes where the plans say to. That'll be where I start tomorrow.
