There appears to be a lot of gunk close to the devices, the kind of stuff you might miss when cleaning.
As most have a raised appearance and do not seem to go over any devices, I would say die polishing lines unless someone was incredible careful
Looking at the continuing line between the A and the N of New Zealand, I agree with the die polishing comment.
3 million struck at the Royal mint, London in .500 silver. I think there are many available for less money https://en.numista.com/catalogue/pieces5690.html
It looks totally unoriginal. Most of the lines on your coin are hairlines - probably from normal circulation. The seller got a good deal!
