I got to do some back-riveting for the first time, and it went amazingly well. It seems much easier to get consistent results back-riveting than normal riveting, at least from this session's experience. Rather than special back-riveting tape, i just used blue painter's tape and that worked perfectly fine. I got all 32 of the the stiffeners attached (8 on each of the 4 skins) without a single bad rivet that required drilling out. Then I back-riveted the 4 parts of the hinge brackets to the left skins, though the shape of those brackets made the process a little tight. I must say, being able to ask Alexa to turn on or off the air compressor in the garage (in the adjacent room to my workshop) without having to go out there and flip the switch is pretty convenient. I also picked up a pair of bluetooth earmuffs that let me listen clearly to music while riveting, which is also pretty nice. What's next? I need to start doing the final prep on the nose skins, dimpling, priming, and edge-rolling them. Looking ahead, it seems like I'm going to very soon be blocked again by the back-ordered VA-140 (trailing edge extrusion) parts, so I may need to pick another section to work on next.