Keeps reminding me of how we all do this in every job, not just planes. My cousin is a plumber and he says the same thing about old buildings, you learn your six blocks of pipe and you know them like your own hands, but the whole city runs on miles of stuff you will never touch. The doc says 175 miles but nobody on earth has walked all of it, not even the people who built the thing. We just trust the parts we can't see because the plane keeps flying, and most days that works fine. It only stops working when a wire in some run nobody has looked at in ten years picks that week to chafe through. So your 200 feet is probably normal, most of us live in a closet and just call it the whole house.