Can any of you either tell me anything about this mill or point
me to a resource for reading up on the Karat mills?
Here's a couple sources. I've seen this mill in a couple variants,
notibly withour without a guard around the large gear wheel, but so
far as I can tell, all of these are essentially similar.
Contenti's listing doesn't call them Karat mills, but I think
they're essentially the same.
This listing shows a couple models, plus a range of optional pattern
wire and bracelet wire rolls for the mills, which are the Karat brand.