I emailed Mike after my last workshop session. I was dismayed and frustrated with my mistakes and unsure of whether or not I needed to replace the parts. Mike agreed to come over this evening to take a look at the mistakes and give me some guidance on anything I might need. Turns out that I was over-reacting! While the countersinks are overdone, they will not present a significant weakness. Additionally, while the one hole is slightly outside of edge distance tolerances, there is more than enough support elsewhere for it to not be an issue.
Mike’s visit was an excellent opportunity for me to get set up for priming. Here you can see the rear spar for the horizontal stab after priming. The process is much easier than I had imagined, and I’m really pleased with the results from my super cheap harbor freight gun. The cap on the paint container does leak if you don’t keep the gun upright, so I’m going to have to figure out a solution to that problem. My confidence is restored!