You’ve got the point. The the right way to do it is working with two different views, each one with its own background image. You can use planes if it’s easier for you. Then you can join’em together. (There are as much ways of modeling as blender users, I think). You could help yourself making some sketches. I mean, something you can use as background images. Also you can try the new Bmesh system, wich simplifies the way of working on such complicated meshes.