I don't do a lot of weathering in cockpits. I don't do much anywhere, but especially not in cockpits of fighters. Making them look worn is OK, but making them look dirty is incorrect IMO. If you have ever been in an airplane that is upside down (I have!) you know that every piece of dirt, mud, gravel, charts, and everything else in there heads straight for your face. If nothing else this insures that dirt won't stay in one place very long.
I usually start with a base of enamel and then switch to acrylic for detailing. For switches and controls I use a #20/0 brush for them. For instruments I put a drop of white enamel in the bezel. When it's cured I but a drop of black acrylic over it. When that has cured I scrape the needles and numers with a #11 Xacto knife blade. The black acrylic will scrape right off, the white enamel is tougher and will stay. Once that's done a drop of Future in the bezel gives it the appearance of glass over the instrument. Silver Sharpies can be used to pick out studs and switches.
Edit ... I forgot to mention: Put some spots of color in. Find some controls that are red and make them bright. A few shots of color will really make a cockpit stand out. At the same time, get your colors right! Indicator lights, CRT screens, MFD's, etc. are never bright red, green, or yellow when they are off. They are very dark.