Continued with the center section per instructions & prints. No real surprises here. The fwd flange of the F-715 ribs on both sides needed to be trimmed to lay flat behind the flange of the F-704. Seems like a lot of people have had that problem. In my case, it only needed about 1/16" Match drilled everything that wasn't already match drilled & then flipped the assy over in preparation for disassembling it for cleanup dimpling etc. There were other small tasks that got accomplished today, but mostly a lot of research about which holed get dimpled, which get countersunk etc. Theres a lot of stuff going on in this simple assy. EDIT/WARNING- This is future Terry talking to you from 11-20-20. Do you see on the F-715 rib where I've written a sharpie to enlarge that tooling hole to 5/8"? Don't do that yet. It's on drawing #22 to enlarge that hole. You do all the rest of the ribs similarly, so I just did it without really thinking about it. Turns out that the F-770 side skin stacks on top of this and gets riveted to the web of this rib. Would have been a lot simpler to wait until it was clecoed together and poke a hole through both layers at the same time with a step drill. As it is, I'm going to have to nibble and file out a hole in the skin to match the one I put in the rib. Also, there is a note on print #28 to drill this hole based on a pilot hole in the F-770 skin. That hole isn't co-located with this one. it's aft about 2" So basically, I've got two prints that call out the same hole in different locations. To compound the confusion, the note on print #22 is on the full size print, but not on the preview plans, which is usually what I build from unless I can't read something tiny and need to refer to the big one. I discovered the mis-located hole when I clecoed the F-770 skin on, then looked at the preview plan and didn't see anything telling me that I should have drilled based on the tooling hole in the F-715, even though I knew I had read that note somewhere. Thought I was having a senior moment, so I called Tech Support. Sterling told me that it was no big deal to locate that hole fwd based on the tooling hole and then just shoot a rivet in the aft location. The next day, I discovered the original not, and figured out the multiple callout situation I just described above. Got curious and did a little poking around with Google and found a build log where somebody had drilled a 5/8" hole in both locations, even though they don't have e.d. between them. Claimed that he had called Van's and talked to Guru Ken Kreuger who said that was cool. I called Van's back and talked to Gary in Builder Support. Explained the situation. He agreed that it was weird that the callouts were different depending on which print you looked at, but said either hole location was fine, or If I wanted to drill them both that would be ok as well, which confirms what the build log I read indicated that Ken K. had said. At this point, I'm just going to open up the front one in the skin, but if I end up with too much stuff coming out of that wing to run through one 5/8" hole, it's nice to know that I have options.