Eric & all: I got such a stem from John Barron at the velo swap a month + ago.. It is very nicely made with many special features as you describe. I think they must be a product of the French aluminum specialist bicycle company "Caminade." I have a small blip on them in the CR French section..
http://www.cyclesdeoro.com/
Jeff Groman at Kingston Classic Bicycles sent me a picture of his stunning bike by this unusual company.
Dale Brown