I bought two SP101 revolvers that Jack Weigand had obtained directly from Ruger, or a Ruger distributor, when he was still doing custom 'smithing. I did not deal directly with Jack Weigand, however; a local dealer of high-end handguns placed the orders, with Jack Weigand, who advertised such ready-made "Tame the Beast" snub-guns on his site, so these were new handguns when purchased by me. I did not initiate the order for the first one; a state trooper had initiated the order, for one Beastie, and the dealer decided to request two of them. I bought the second one, from this initial order. Perhaps I asked the dealer to order another one for me, or perhaps the dealer decided to initiate the order, knowing that I or another customer would soon snap it up. (It has been a while.)
Though Jack Weigand no longer does custom work, there are still pistolsmiths who will accept orders from customers, who will source the new handgun through the maker or distributor. Check the 'smith's site, or call and ask.