I deburred the holes in the spar caps and spar webs. I also marked the caps and webs where I need to do the countersinking. It looks like my microstop countersink will work for most of the holes except where I have to countersink on the spar caps. The microstop is too large to fit because the top of the spar caps get in the way. I will have to do this manually/by eye using a drill extension to hold the coutersinking bit.
I noticed that some of the holes were not drilled exactly plumb. I have marked these holes and will still try to rivet them. The rivet heads might move enough to sit flat against the main spar web. If not, I will drill these out and rivet to the next size rivet. I am going to purchase some drill bushings so that I won't run into this problem with the next spar.
Spar cap and spar web marked with locations of countersunk rivets.
