You can try this:

maiso@wanadoo.fr

This is the last contact information I have for Michel, Grandson of the founder of the company. I last had contact in perhaps 2006 or so. He reads, writes and speaks English.

This was an address for the firm:

13 rue Clement Forissier, Saint Etienne

Since you likely won’t ever meet anyone who would argue with you about what the case label looked like, you could likely use the form from one of the catalogs. A graphic artist could probably work wonders with this:

[Linked Image from i.ibb.co]

Best,
Ted