pfeist,
Look at the "Frog" at
http://www.avatartools.com/Merchant2...ategory_Code=L
The've got a "Frog" about all of the little mini-lathes. Take a peek at the threading figures for the Clisby compared to the others. It's pretty pitiful.
And Adapting a Taig for threading just simply Sucks... (tried that, and ended up selling the taig.)The Sherline is probably the easiest to adapt but with a 20tpi leadscrew, coarse threads might be a little tough.