Riveted both skins to horizontal stabilizer. Did not rivet top of aft spar or tip ribs. Must first complete assembly of elevator halves to the elevator control horn, then use the elevator hinges to establish the location of the hinges that mount to the top of the horizontal stabilizer aft spar.
Must wait until elevator is mounted before fiberglass tips can be installed, along with the tip rib extensions.
Stabilizer appears to be flat/planar with no rock; hard to tell with the cleco's still in place for the aforementioned later tasks. Set the stabilizer across a corner of the workbench to check.