If you ever look at the map from when they get it in the attic and from then on in the movie, you will notice that it goes from being completely dirty and torn and ripped to basically clean and new and it continues throughout the entire movie. I don't know why they'd keep switching it like that, it doesn't make to much sense.
They had two maps. One was the old pirate map and one was the new map of Astoria. They bought it at the store in the extended full length cut of the film.