Heritage Charts have uncovered some quite unique and extremely rare Cook material from his first voyage to New Zealand in 1769... These two (North and South) are finished copies of Cook's original surveys.
Heritage Charts NZ100N
Heritage Charts NZ100S
The British Hydrographic Office under it’s 2nd director (Hydrographer to the Admiralty), Capt. Thomas Hurd, published a derrivative of this chart as one of the first ever ‘official’ publications by that office in 1816. You can view and read more about both of these that charts at Heritage Charts
Here is one of Cook's working charts, this one drawn in the hand of Masters-Mate Richard Pickersgill. It is credited to Cook as the first complete survey of New Zealand and formed the basis for the Yes the real thing does actually look as though it went down with the ship and was dried out over the barbecue!
You can view all of these charts at Heritage Charts World Collection