Once in a while. $$$$ but a sweet upgrade.I wonder if they turn up on eBay: looks like a nice upgrade.
In that dial upgrade thread that I started some time back (maybe I will get that done this year) there are some pics of a Stelling dial that I borrowed from another site. Google Stelling dial or Stelling Logan ... you should get a couple of hits.
There is one for a Sheldon on there right now. That's a steal if we had a Sheldon.