Well, if you use acrylic paints thinned to the perfect consistency with a soft brush, you can acheive airbrush result without the stroke marks!!
I had to sand the surface with 2000+ and up grit sandpaper, just to make sure it's even smoother
*enamel paints are the worst!
Since the pics qualities are not that great, so it's hard to tell how well the paint job's done!