Anyone or any shop can pay S&W to make a run of whatever gun they have or a mix of features. This is how Talo, Bone Collector and Big Rock do it as has a name that slips me who had a batch of custom 5" 500s made.
Sounds to me this example was a marketing attempt and tie in with the show....etc. S&W doesn't likely have any personal affiliation with the guy who called up and either hand picked components or told the PC to do it for him.
That said, let's all get together and commission a batch of 500 PCs identical save for caliber to the 3" 460 XVR PC
. The 460 always gets copies of the 500 specials like ES, Bone Collector...etc. That 460 PC is a dream, I just need it in the king of pistol calibers
