Got the skin lined up, cut a hole through it for the antenna, and used a step drill for the first time. LOVE that thing! Clean holes, no burr, no problem. I ended up putting an angle on the holes because the antenna was going in at an angle, so I used a slightly larger grommet and will let it smush out oval shaped. There is a countersunk hole to attach the skin to the rib right next to the rivet that I can't use because the "puck" from the antenna is in the way. I don't think it will be a problem because of the other rivets and the antenna itself, though.

Got everything attached and cleco'd. I still need to check alignment, then I can let the riveting begin!