Empennage: Elevators. Trim tab reinforcement doubler and gusset riveted.

The trim tab reinforcement doubler is attached to the front spar with AN470AD3-3.5 rivets.  

These are 1) hard to access and 2) round headed.  I don't have a rivet set for AN470AD3 size rivets.  I do have a squeezer set but I didn't have a bucking bar to mount it in.  We tried the below, but it wasn't deep enough to clear the skin over hang.

So we just bucked it with my narrow flush set which is acceptable (see 3.3.3.2).

Wasn't too bad to get in there.  Just took some planning and care.

Here's what the shop end looks like on the most difficult trim tab reinforcement doubler rivet.  Pretty good actually.  You can see we scuffed the one pop rivet there, but that's not an issue.  We did have to drill the original rivet we placed here since the bucking bar slipped against the nutplate and destroyed the shop head.

Squeezing the gusset rivets isn't easy.  Had to upsize one to an AD4.

We had to drill out the three upper inboard rivets holding the skin to the rear spar and piano hinge since I mistakenly closed things up before riveting the gusset to the rear spar. Not a problem and those rivets were easy to hit.

Next up is sealing in the foam ribs, closing out the lateral tabs and bending the forward skins shut.