Here are a couple of shots of what we did the other evening. We put the skin around the internal structure (ribs and spar) using clecos which are basically pins to hold the skin in place while you are riveting.
The tricky part is going to be riveting the middle rib and spar because you have to reach down through one of the ribs on the end with a tool (bucking bar) while you are using the riveting tool from the outside.

And here is a comparison of our stabilizer and one of a fully-built and flying RV-10. You might have
to click on the image to read the text but the part of the tail that has a rectangle around it is what we have so far. Once we finish the stab (short for stabilizer) we will move on to the rudder next!