Since I don't have the dimple dies yet, I looked for the first part I could do without dimpling. The counterweight bracket fit the bill perfectly. Small, 54 rivets, completely self-contained, so I went for it. It took me a few times doing the dry fit-up to be happy with it, and then I cleaned it all with alcohol and put it together. I noticed that the right-angle brackets block access to one of the rivets (well, to the rivet gun), and luckily the brackets were only Cleco'd in when I was trying to get that rivet.
I couldn't figure out why my Proset XT2 rivet gun wasn't working. I figured there wasn't enough air pressure (the compressor kept turning on to try to keep up) or that the gun itself was broken (half price on eBay, the serial number on the top mysteriously scraped off but the one on the bottom was there). I noticed there was only the one nosepiece when I got the gun (did I mention half price on eBay?) but didn't think much of it as I pulled the 50 3.2mm rivets by hand, but when I had to pull the 4mm stainless steel one by hand, I decided to try again. Turns out that even with the sad excuse for a compressor, the gun pulled the 4mm rivets just fine. So, I went online and ordered the nosepiece for the 3.2mm and the 4.8mm rivets, because I know I will need those soon.
Also, Allison and Rosie (the riveter) got into the act, each pulling one of the 4mm rivets.
When all was said and done, there were a lot of used mandrels, only one rivet that needed to be drilled out because I put it in the screw hole, and everything is good!