The lower longerons in the forward fuselage are bent and twisted in order to lay flat against the skin. Dick does a great job of defining the initial bend to use for these longerons in the plans. However, to get the longerons to lay flat across the entire face and length of the angle, you have to tweak the bend and twist as needed by your individual side skin. This turns out to be a somewhat time consuming process. Image 1 shows the right longeron very close to its final configuration. As you change the bend, you need to simultaneously change the twist. I found that it helps to mark the longeron with numbers as shown in image 2 to allow focus on bending the proper zone. Image 2 also shows an easy to make tool that twists both flanges at the same time. There is also a balance to be maintained between the amount of adjustment made to the longeron vs the amount of pull-in allowed for the skin. You don't want to pull the skin hard enough to show a pucker. Image 3 shows the left longerons drilled in place.
