Yes, it's already in game
Simply don't repair your paintwork and a few weeks of general use will have your ship looking scuffed and scratched.
Everything else - hull, mods, integrity - can be kept in top condition without affecting the looks.
In 1.3 the "Repair All" button now excludes your paintwork, so it's much easier to achieve this effect if you want it.
In reply to the OP:
I'd be happy to pay for the cockpit mods that others have mentioned.
And when our pilot avatars become more relevant, some customisation for them; goggles, aviators, flight jackets etc would be cool.