A few years ago, early 90's, there was a shop called Antique Automotive that dealt with Hot Rods, Muscle Cars and Specialty Cars. They also sold restoration parts, both new and used, and had a back lot full of project cars and parts.
On one of my visits I found a very demolished fastback Mustang, and it was a 1966 Shelby GT 350 that had been pulled out of a ravine somewhere in New Mexico. The car was pretty stripped and the roof was mostly caved in, but, it had one very important part still on it, the Shelby Tags and chassis numbers. That, as the shop owner told me, was as good as gold to Shelby collectors, as they could legally replicate a Shelby car with the remains, and it would be legit on paper.
So yes, there might be a Shelby recreation with legit numbers out there and no one is the wiser for it. And then again, this could just be the end of the line for a legit Shelby, if it is a real Shelby.
Until we hear otherwise, that is pretty much it.