Did a bit of research to figure out if the instructions were ever going to tell me to flute or not (they don't), so I went ahead and flattened the ribs out pretty well with the fluting pliers, then assembled the vertical stabilizer skeleton (sans hinge brackets, of course). Couldn't help myself reading ahead one more step to see that I attach the skin for some match drilling, so I attached the skin - taking extra care around the leading edge considering the cautionary tales I've read only (rib-tips not properly rounded = marking against the front leading edge). Thankfully, it looks like I avoided any of those issues; but I did get to experience the joy/frustration of attempting to align the skeleton to the skin holes; wasn't too bad though - had to use a punch here and there to manipulate the rib through a skin hole, but got everything all clecoed together - marking the first time in the project that something actually looked like an airplane part!
By way of tracking, I also final-drilled one side of the skin (tagged with a green arrow to remind me)