“There is also strong evidence to suggest that the map was a deliberate hoax, rather than a modern recreation that had simply been misinterpreted as genuine, as evidenced by the fact that its creators used part of an authentic medieval volume and overwrote it to make the map appear more legitimate.”
And that it was written on an authentic medieval volume is proof that it was a hoax? This researcher makes a leap of faith. The exact opposite conclusion could be reached.
I often use a base map provided by my client and then add my own results on top. It would make sense that they would use an existing map as a reference.
I’m guessing though that the makers of the N.A. map weren’t involved in slicing the two together. “Ikke na! It is MUCH farther away than THAT!!”