Thanks for the Hartmann text, Frank.
Ok, now I remember where I got the "near Paris" bit from ... Hartmann's massive tome. Trouble is, when I first tried a translation of the text (as posted above) it did not seem to make anything clearer. And now that I have tried again (at nearly 1:30 am, while half-watching the Glastonbury festival on TV) and using an Internet translator, it still seems uncertain.
Also, (and this is in no way getting at Frank) I am not convinced that Hartmann's text, which is listed under "Le Maitre" rather than a listing for "Lagny", really helps much.
Am I right in thinking the basics of Hartmann's text is that "Lagny" is possibly a signature used by a modern company known as "Le Maitre" and that somehow there may be a link with the 1930s work of Schneider who also used the signature "Le Verre"? [The date of 1990 for "Lagny" is only listed in Hartmann in the section for "marks" - it is not stated in the main text and "Lagny" itself is also not shown in the main Index.]
By the way, according to Edith Mannoni in her book on Schneider, "Le Verre Francais" was one of the brand names for "lesser" pieces by Schneider. I suppose "Le Verre", as quoted by Hartmann, could simply be "Le Verre Francais" but missing the last part of the signature.
Anyway, I'm still as confused as I was a few years ago, and I still cannot find any other refrences to "Le Maitre" (or "Lemaitre") as a glass company or signature.
Can one of you linguists out there please give an accurate translation of the Hartmann text? And does anyone have any info on "Le Maitre"?