Does it also come with the original .38 Wadcutter top end or no? (Maybe it never had one...?)

As to validity, ANYTHING is totally possible. I would definitely want to see pictures and a serial number range and hear more details and even some name-drops if I were trying to come up with an argument for validity.

As the the idea of 9mm through a 52, we have discussed this a few times and there are a couple points I would make...

It will be my position that a 9mm target gun is a lot easier to find ammo for than a .38 Wadcutter and it will hold more rounds but it’s my firm position that nobody is going to alter a 52 to make it shooter 9mm more accurately than it would with .38 Wadcutter unless it’s some absolute craftsman genius and if he can do it for less than a couple two or three grand, let me see it! And before we forget, I really want to know about the magazines this pistol will be using. That’s a side discussion that matters.

And it cannot be ignored — but the S&W Performance Center did a pretty great job of (somewhat, nearly) doing this project and the result is the Models 952, 952-1 and 952-2. And I own two of them and neither will do on paper what both of my 52-2’s will do, at least not without some magical ammunition elixir that I have not yet discovered.

952’s are phenomenal but if you HAVE one, don’t race a 52-2 for pink slips unless your junk gets hauled around in a dump truck.

These are merely my opinions!