Somehow I missed installing the six universal head rivets in the reinforcement plate at the bottom of the forward rudder spar. Without major disassembly, it is not possible to install solid rivets. I called Van's and they said I could use Cherrymax blind rivets instead. I ordered a CherryMax Grip Guage, a Cherrymax rivet puller and a variety of CR4213-4-4 -5 -6 -7 rivets. Since I have to wait for the rivets to come in the mail, I started on the right side Elevator counterbalance assembly.