I belong to an organization called GenVerrE. (it is a blend of the french begining of the word genealogy and the word for glass which is verre). It is comprised of descendants of glass and crystal makers and many Stenger descendants are members, including myself. The book by Etienne is in French. GenVerrE sells it. Go to www.genverre.com
we have attempted to translate much of the site into multiple languages. http://www.genverre.com/faq.php?lng=fr
this takes you to the book. I have some pieces of it translated into English. I am also the co-moderator of the Moselle genealogy list for Yahoo Groups. Many Stenger descendants are there too. I can't attach files here but I can on either Genverre or Moselle genealogy lists. Genverre is predominantly a French writing list while Moselle is predominanty English wrtiting. Both have members from multiple countries. I am not the expert. Luc Stenger and Marie-Claire Stenger Christopher get that title! Luc belongs to both lists, Marie-Claire is an officer in GenVerrE.