Test results :
see the figure below
Actually the nodal point location depends on the aspect angle ( ß ) from the optical axis of the lens.
There is an INFINITY of nodal points. All are located at a distance (D) that goes from 17.5 mm from the lens front to 4.5 mm from the same surface. That is a 13 mm range along the optical axis (i.e. about two focal length !)
Suppose that two objects (one near the camera and another farther away) are aligned on the main optical axis (i.e.ß=0deg)
When you rotate the camera around an axis which contains a point which belongs to the 13 mm range, you shall have two (and only two) other different positions where the pair of points looks again aligned (i.e. the closest hiding the farthest one). The first position give a ß angle and the other is opposite and symmetrical (-ß)
As the lens is geometrically symmetrical AROUND the optical axis, the above property is valid for the half-conical angle ß in the global space (in three dimensions).