Two + hours of non-stop countersinking was the theme of this session. I don't know how many I did but my arms ache and I'm glad it's over. I machine countersunk all of the #30 holes into the structural parts that will attach to the dimpled firewall. Then I countersunk all of the nutplates attach rivets per the plans. Care must be taken to do the proper side of the part in question. Van does a great job of spelling it out, but it's not screw-up proof. I also scuff and cleaned the parts for priming. Today it should be almost 50F and sunny so I'll run out and prime everything so next session I begin riveting.
I drilled and cleco'd the parts to the edge of the bench to ease the process.
This is a close up of what it looks like when its done.