Back in the day there was a lot of rebranding going on. Vivitar, Sears, Hanimex, Porst, Lester Dine, Soligor, Miranda, Centon, Sirius, Sunagor and a multitude of others, all made by the likes of Kino, Cosina, Tokina, Chinon, Schnieder Optik, Olympus etc.
A lot of companies also copied the optical and lens designs of others. Look at the Russian Zenit lenses like the Helios 44 which is a ripoff of the CZJ Biotar design of the exact same focal length and aperture. The Russians copied a lot of the German lenses, so it's not uncommon for some old glass to be virtually identical, or at least very similar. I wouldn't rule it out totally because you never know what went on behind closed corporate doors 40 years ago but, I would be surprised if Nikon rebranded a 3rd party lens and brought it into their own stable. I know the E series were the "poor man's alternative" in terms of their component materials. Maybe to cut costs they did use 3rd party housings but dropped in their own optics?
At the end of the day, it matter's not. It looks pretty decent optically and what you do with it is far more important.