I made some pretty good progress today. I figured out my slot cutting for the ribs, created a jig for the assembly, and also started on the leading edges.
First, the rear spars. I used the main spars as the template to draw the rears, but since the rears are also narrower, I had to reduce the width to 3/4". I also had to transfer the slot marks, and you can see how I did that in the following pics:
From there, I took all 4 spars out into the garage and setup my 4.5" grinder with a carbide cutoff wheel. Yes, the same wheel that helped me create a new exhaust for the Porsche can cut nice clean 1/16" slots too! Here you can see the table jig I setup to feed the spar nice and straight.