"Maxprop" writes:
Perhaps I didn't look far enough for accessories. I considered a Grizzly
G1495 but abandoned the idea because no one appeared to be selling that
thread in adaptors for the four-jaws, or faceplates, except for Grizzly
itself.

Both Teknatool (SuperNova) and Oneway have 1x12 adapters for their
chucks. Heck, they support pretty much ANY lathe (Oneway custom taps
on request). Lee Valley has 2" and 3" faceplates for 1x12, and if you
buy just the insert from Grizzly you can attach it to any home-made
accessory you want. You can buy 1x12 taps too although they're not as
common as 1x8 taps.

But yeah, 1x8 is much more popular.