Before joining the fuselage halves I really should have shown the rear fuselage doublers. These are two pieces of sheet that are mounted cross grain to reinforce the horizontal stabilizer and tail wheel locations. As seen in the bottom photo the fuselage bottom is trimmed to allow the tailwheel mount to glue to the bottom of the fuselage. The small former (F4) mounts between the fuselage halves just in front of the notch for the stabilizer. You can see the laser etched notch marking the centerline of F4 and the centerline on the fuselage floor.