Don't know if I can good pic of the adjustable shanks. I'll see what I can do tomorrow.
The EC has a fingermate shank: http://www.fingermate.com/ . It is knd of a pain because if I carry something heavy or otherwise apply pressure the thing opens up. Since it stays connected I don't think the ring is at risk but I keep having to snap it shut.
The shank of the RB I like much better. It is not going anywhere. If it is open there is a spring that keeps it closed and it has never popped open. Any new ring I have made will use this shank unless something better comes along. This looks like the site: http://www.superringfit.com/index.html
ETA: I am also a silver/goldsmith as a hobby [for 40+ years! ACK!]. Guess I should haul some of my hand made pieces out and post them too! LOL! I would not venture to try to make an arthritic shank. The machining needs to be very precise. Typically what happens is that a ring gets made, the shank is chopped off, and the new, adjustable one is soldered in its place.
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