Are you sure about the "Pierce-Packard"?
I know the car you mean, but from what I can find, it was owned by a Mrs Gordon (who may or may not have been called Ruth) who was the wife of someone called John D. Gordon from Norwalk, Connecticut, and not Ruth Gordon the actress.
At least that's who the Packard Club thinks owned it, and also the daughter of James Melton, American popular singer and car collector, who apparently acquired the car from Mrs Gordon of Connecticut in 1950.