Credit is due to William Kelly, a truly accomplished and veteran JFK researcher, for finding the material linked above.

There is much to digest. Let's start with this:

Some 15 years ago I became aware of the name Silverthorne within the JFK assassination context. "Joseph Silverthorne" and "Silverthorne Stables of Paris" were offered as tantalizing clues by two authors -- one famous, one infamous -- sharing a Lancer podium.

The name is rather uncommon.

The linked article is by one Andrea Silverthorne.

More as it develops.