They obviously didn't know about the Cobra heads. They were 6 bladed, and very similar in shape from back in the 50's.
or the Jewell Leadford 6 blade, which is so close in design it looks like they copied it... circa 1975, or the Hamilton 6 blade rear tails were more like the f-18 (?) V shaped, circa 1974, or the Bee Stinger 6 blade, again, with V shaped rear flaps, circa 1987.
First ? I don't think so. Only ? well... yeah, these others died out. Hmm I wonder why ?
These may work. Anybody out there hunting basketballs ?
ChuckC