S&S puts in a standard order continuously with Taylors, and takes pretty much whatever they send. I spent an hour with the owners talking about the supply and demand for Uberti C&B stuff, and the comment was that they are always short supplied. They can certainly put you on a wish-list for the stuff, I am waiting for a few goodies myself to arrive. Patience is a virtue in this game. They do not order all models, but they will tack on special requests to their orders if you ask.
You could not ask for better folks to deal with, in any event.