OK, I've stepped away from the grinder. At least for now. It's 107 and stupid humid, so I won't do anything until tomorrow morning at the latest.
The door's forward edge sits behind the fender's trailing edge, but that's b/c I have the door on and am installing the fender (repeatedly). If I had the door open, put the fender on, and then tried to close the door it would overlap the fender and press against it, preventing the door from closing (and making a mess of the paint job).
I'll try moving the hinges out more - loosening them at the jamb and driving them outboard. I'll try "ovalizing" those holes. Hey, I'll try Vaseline if that will do the trick.
Tomorrow.