It was broken in at 100,000, and well loved but getting up there in age at 200,000. Here at the upper eschelon of distance you sit, having crossed the 300,000 mile barrier is a testimate to both what you drive and who is doing the driving.
 
There may have been a new engine along the way, or maybe one is to come. But that little surface rust on the body isn't enough to scare you away from this specific VIN. You'll throw another engine at it, and another if you have to. After all, your steering wheel is so worn by your hands alone you could likely access a fingerprint scanner with it.