There was some dealers a few years ago that had them for a while. But you're right, I haven't seen them on any lists for a couple of years now.
If you're Jonesing for a single action and the Ruger Single series of guns doesn't do it for you I would suggest you consider a Pietta 1873 in .22 from Marstar. The fit and finish of the Pietta blows the HA gun cleanly out of the water. It's more money of course but you'll get a very nice gun with a much better looking sight setup than the lumpy adjustable option on the Ruger.