Riveted the vert spar to the doubler and the horns to that assembly. This was done using the squeezer. The rivets called out in the plans were a bit too long according to my rivet gauge so I ground each rivet down a few thousandths to make sure they didn't bend over during squeezing. That took way more time that it should have but oh well, I didn't ruin the part. The black primer and aluminum are a nice contrast. The flush rivets look pretty decent. At this point I feel like I'm better at bucking than squeezing.