I like the angle of the 10,000 mile test. Who wrote it?
If it was Titus, then I'd guess the car was part of his unofficial deal with Shelby. He probably just drove it around in his normal life, racked up 10,000 miles, then decided to write it up as that.
I doubt that any car mag writer (even Titus) went to CS in '65 and got the approval to simply do a 10,000 mile test on a GT350 for a magazine article. Not good return on investment for Shelby. In that same 10,000 miles, Shelby would've gotten 10 or more different magazine tests out of the same car.