Because my elevator control horn sticks down about an inch further than the plans specify, I needed to ensure that the fabric covering doesn't interfere with it when it's shrunk tight. Since there needs to be an access hatch there anyway, I decided to make it out of 1/8 inch plywood. This also requred me to build up the bottom stringers so that they are flush with the new access hatch.
Total Time: 3.5 hrs.