I had previously primed the parts that attach to the forward mid-fuselage bulkhead and I finished final assembly of those parts today.
I started out by riveting the seat rail attachment assemblies.
I then countersunk the holes along the bottom flange of the bulkhead. These (and the corresponding skins holes) were final-sized and I had already clecoed up the bulkhead with the forward fuselage parts so I was able to do the countersinking now.
When complete, I lightly brushed the countersunk holes (and the gear leg areas that I had widened) with some primer.
I then riveted the remaining nutplates.
Next, I bolted the parts together and torqued the nuts. This was followed by riveting everything into place.
Success! I applied torque seal and marked another section of the plans complete.