The story does not state that she was famous. The end of that story explains who she was: the wife of a Hollywood studio executive. Which for the Average American who is outside the LA social circles has no meaning. There is no fame in the story for anyone, only the great circle the double auto shotgun took.
A few minutes on IMDB does not produce much in the way of historic studio executives. Only recently have they started adding data on producers and directors. However, there are so many other positions withing a large corporation that this source would never document them. Nobody cares about the accountants until they embezzle the money.
Google does not even help.
It leads me to think that Mr. McCall is just another man lost to history or that it was a good story, but only story.