stangfanatic - at what pressure are you airbrushing ? For tight places, I usually don't go over 5psi. The "turbulence" of reflected airflow may be disrupting the paint by reflecting off the surfaces in the "nooks." Lowering the pressure and gradually building up the paint in light coats may give you a more even finish.
I try to assemble the main airframe, minus fuel tanks, bombs, etc, and without parts that are easily broken (antennas, pitot tubes, etc. I will even sometimes paint without the wings, but only if the seam will not require filler or sanding. It may take longer this way, but I spend less time cleaning up the errors.
Hope this helps you out ! Good luck !