This map is most certainly NOT from 1650.
It appears to be very old but has details, scale and orientations that were not refined to this level of accuracy for many years to come. It is likely made by a non professional cartographer to depict boundaries of the 1650 period for a specific purpose.
It is however fairly accurate in depicting the bounds of Rehoboth prior to the North Purchase and conveniently includes all the needed reference points to extrapolate that area. It is my opinion that this map was created in the late 1800’s or early 1900’s in the old style for teaching the history of the Rehoboth area. The color overlay features show how well suited this map is for that.