I finished countersinking the #40 holes in both spars. 
I installed the nut plates on the spar.
I had a hard time making the #30 countersinks look really concentric. The pilot of the countersink tool doesn’t catch to nut plate until a most of the material has been removed using the countersink bit. Before the bit catches the nut plate, the location of the bit is not will controlled. I’ll sleep on this and work on it while I’m fresh. 
