Preparation for the front assembly took a bit of time to understand. My kit has the adjustable seats and these instructions have to be read with chapter 15. I spent a bit of time trying to find the extruded angulars without luck and just happen to glance at someone elses construction and notice the angulars were differnt? Checked the adjustable seat instructions and this is where the different extruded angulars are described. Also there was a jig for drawing some additional holes. All starting to come together.