There are plenty of ways to do this and this is a basic one.
Since there are no cross sections on the 3-view, I developed some from the initial exercise where I developed the fuselage from a cylinder. I am linking a GMax source file here to get you started.
You can download the GMax source for the cross sections here:
This file contains only the cross sections, no calibration box. you will need to merge this code to your scene. To do that, open your scene, then select file/merge and browse to the unzipped file of the cross section.
Once you have this loaded, we will construct the fuselage half using the following as a guide.
In this exercise, I am using the original 3 view left/right side drawings as they match up better with the other sides than the real world side view I developed.