First, welcome to the build.. No pressure, no dead-lines.. Anyone can play, and at any time..
Now regarding the wash... A wash is used to add depth rather than show wear, in your case... After using a wash to darken the recessed areas, you might try drybrushing with a lighter shade of the base-color.. Then drybrush over the raised detail, just catching the edges of the ribbing... Then lighten the color again, and go over even more gently than before. Next time, your drybrush shade should be almost white.. Since this is an interior with a limited view, it won't hurt to exagerate a bit.. I always close up the fuselage with tape and try to see what I can see, then take it apart again, and do another thing..
Got any pictures of what your Mitchell looks like at this point?