It's my understanding that all of those beautifully weathered boats are dramatically over weathered. The boats were serviced between patrols and, while not dry docked or repainted every time, they received significant attention. Of course that changed as the war went on so they would tend to be more heavily weathered in '44-'45.
I'd say you're spot on with the #2 approach. with salt build up and some spotty, light rust. You're probably not far off on the anchor rust. It rarely, if ever, was used. Where your boat patrolled would be as big a factor as anything. A North Atlantic boat would not have seen the fading that a boat in the Med would have, for example.
As they say, less is more most of the time.