Not a whole lot to report for this post. My friend Rishab is coming over on Sunday to help rivet, so I wanted to ensure the leading edges were dimpled and ready to go. First step was to rivet the nutplates to the fuel tank splices. Shown here. 
And then all that remained was dimpling the skins. 
Getting these blasted rivets out of the tanks is proving to be far more difficult than I had anticipated, and I was expecting it to be difficult. I bought at USB “borescope” camera off of Amazon for $18. Its a cheap bit of junk but it serves its purpose. With this camera I was able to remove many other rivets. Next I tried sloshing water. This brought out a few more rivets, but at final count I was still short. Finally, I gave up and drilled the baffle off of the right tank. Drilling rivets was easy. Removing pro-seal was not. I destroyed the baffle in the process and had to order a new one from Van’s. I’m now 5 rivets short of having them all. I’m not going to remove the other baffle as I’m convinced I can get the remaining five with a combination of the camera, magnets, and sloshing water.
I attached the camera to one of the telescoping handles I have for an inspection mirror. Then I affixed a piece of string to the very end so that I could manipulate the angle of the camera inside the tanks. It worked very well. Lighting was a bit difficult with the high reflectivity of the aluminum.
Here’s how I’m keeping track of the rivets as I remove them. 
Here is the tank after I removed the baffle.
The proseal I will need to deal with prior to installing the new baffle. Not going to be fun. 
Here are some interior pictures I took with the USB camera. 
About a month ago, I made a major mistake on my fuel tanks. Like a complete idiot, I installed the right z-brackets on the left tank and vice versa. I was mortified when I realized what I had done. I decided to allow all of the sealant to completely dry so that I would have the best chance of retrieving the rivets from inside the tank. If the sealant were still tacky, I would have no luck.
I was dreading drilling out the pop rivets. I thought they would be more difficult than normal rivets. It turned out to be super easy. I drilled out all of the pop rivets on both tanks in probably about 20 min. The center punch finished the job.
All that remained was to retrieve all the pieces from inside the tanks. I should be able to just shake them out… right? Nope. Well then, no worries, I have a telescoping magnet and mirror… this should be no sweat! Wrong again. There should be 25 pop rivets in each tank (50 total). After a good hour and a half of shaking, magnet wielding, and sticky tape ball fishing, I had 17. They don’t even rattle anymore. So yeah, now I’m not sure what the next step is. If I have to take that baffle off, I’m going to be sick to my stomach as that is A LOT of work. With that many rivets to drill out, the likelihood of messing one up also goes up.
I’m inclined to say f&$# it. Thats what a fuel filter is for, but I’m probably going to consult Van’s and maybe the forums first. I don’t like the idea of a potential clogged fuel line 10 years from now. *Edit. I posted to VAF here. 
The 17 pieces that I was able to retrieve. 