Today the final hole is drilled for mounting the wings. The six bolts for the main spar are already drilled and matched as the parts come in the kit. But once you get it all together you have to drill the final single hole in the rear spar which aligns the wings to the fuselage. Having got it all lined up and check everything. Take a breath and have another coffee. then check it all again. then, maybe check it again. I finally ran out of excusses not to drill the holes.
Then in goes the bolt and job done. the good bit is you can now for the first time climb onto the wing and enter the cockpit for real.