Here is my thought on the matter:
While the markings probably were painted with a brush, the paint thickness would have been thin scale wise about the thickness and coverage an airbrush would put on the model. Also, the lines painted by hand would have been relatively close to straight and reasonably square. The corners would have been fairly sharp and square. I would have run some tape for the wide stripes and airbrushed it in a thin coat. I would not have worried about them being perfectly straight and the coverage consistent. At a distance they would have looked fairly straight and square I suspect.
When in doubt do some research and look at some photos. In the end it is always your choice as to what and how you assemble and paint the build.