Hello Richard, There appears to be a relevant reference book: Spectacles and other vision aids: a history and guide to collecting, by J. William Rosenthal. It contains references to Chevalier Opticien. You can search it in google scholar via this link: http://tinyurl.com/2u5x7zq There is also an opportunity to purchase it from Amazon, but it's a bit pricey... Hope this helps a bit, Brian ------ Unsubscribe or change to/from Digest Mode at: http://www.lrflex.furnfeather.net/ Archives are at: //www.freelists.org/archives/leicareflex/