I remember the old 16' fiberglass rods that my father had an one was definitely a Black Marlin. It was a black rod with black and white binds and it caught some absolutely awesome kob and a 18kg Steenie in Swakop / Henties in the late 70's
Who made it' I don't know but all I know is that my dad sold it for a lot more than he paid for it because in those days it was a casting machine and could haul big fish and even then it was as scarce as Hens Teeth.
Maybe a brand that got started and went belly up before it took off. Next time I talk to the owner of Blue Marlin I'll be sure to find out from him. He's been there and done that over and over so I'm sure he'll shed some light