Riveted the elevator together:

Trimmed the L angle connecting the upper and lower horns:

 

I adjusted and attached the servo to the trim tab, as well as used a 9V battery to test its movement up and down. The rod and assembly can safely clear the hole, and nothing catches or drags.

I mounted the servo motor, double checked everything, and the elevator is done! I’ll hold off attaching to the horizontal stabilizer until I have a hangar or somewhere else with more space.