Best guess?
Since the alignment, font size, and depth of the "N" impression matches the "K" exactly, there actually was a legit/approved shape called the NK that lasted only long enough to create confusion for guys like us decades later.
The LB shape was changed to 472 for a year and then changed back, for example. Why? No one alive today knows.
The star looks like a post-production add-on of some kind. Maybe a B&M zapped it on all their incoming Dunhills, for example, as some sort of extended warranty thing. (Many larger B&Ms had a repairman on staff in a separate room in the back who could have done it easily).