I finally got some time to work on the project today. Here's what I did...
This is the completely finished right side horizontal stab. (it is upside down on the workbench)
These are the tabs on the inside of the root rib.
These are the tabs that hold the ribs in place.
Next I worked on the elevator...
The first thing I did was add these three nut plates. The two on the left are for the control horn, and the other one is for the hinge.
This is a pic of the end of the elevator. The two holes you see here are transfer drilled from the end cap that rivets on.
This is the end cap. Notice the small brass washers that go on the rivet before installation!
Here it is! All done. End cap fits nicely and looks good. I also completed the other side as well.