Finished up mounting the vertical stablizer (VS). I drilled the rear spar at the upper attach bolt holes using the elevator stop bracket pre-punched holes as a guide (#30 bit). Then I drilled them to #12 for AN3 bolts and installed the hardware. Front VS spar : per the plans I ran strings from the mid-hinge using straight edge along the back of the VS to a point forward on the fuselage that was also on the centerline. I used the rivet hole on the cross brace called out in the plans and it worked great. My angle aluminum that I used for a straight edge extended 14" on each side of the VS measured from the skin and the string at the forward part of the VS was exactly 12 5/16 on each side so it was centered on the fuselage. I tightened the clamps on the front spar of the VS and drilled the 11 holes in the attach bracket, spacer, and VS front spar. I then drilled out the VS attach bracket to HS front spar bolt holes to #12 and installed the hardware. I deferred priming and riveting the front spar attach hardware (attach bracket and spacer) until I the VS in subsequent steps. As an aside, I also primed some of the fwd console and seat ramp parts.
Use the 90 attachement to drill #30 the upper VS rear spar attach bolt holes (2).
Here you can see the yellow alignment strings used to center the VS.
Pictured is the long #30 bit, but I used a 90 attachment to drill most of this holes (11).