looking for a left hand boring bar; C6 or m42 tip , small radius
cutting edge is acceptable. Anybody got a lead on where I can buy one
of these?
....
Why? Explain the job and you might get a better idea how to do it.

The only thing i could think of is left hand inside threading, but he's not
looking for a thread tool. But it got me thinking, I don't know how to cut a
left hand thread on my manual lathe anyway. How is this done?