Sanborn is a small town with around 300 residents. It was named after Sherburn Sanborn, who was an officer for the Chicago and Northwestern Railway for many years.
The original “Cast Jet” was made by a company started by Erlind Hovde in Westby, WI. Hovde sold the Cast Jet from 1940 to 1948.
It appears that sometime later, in the 1960s or 70s, someone in Sanborn, Minnesota bought a pile of these lures that were manufactured but were never sold. They changed the cardboard on the back to use the new Minnesota address. Also, the lure was now called the “Castjet” (all one word).