Seat back drilling
While waiting for Julie’s help, I did a little more on the seat backs. I drilled and deburred all of the parts for the left seat back. It’s turning out pretty good.
Sandwiching the seat back between two pieces of plywood and stacking stuff on top didn’t really do anything to help lengthen it. I ended up getting the whole family on top of the plywood. That did the trick. I got it right to 26-3/8″ exactly.