On Facebook -JOIN I Antique Online.com: Collectors of Antiques and Collectibles.
Here is the link for the group https://www.facebook.com/groups/327133184409134/
Please join our FB group where YOU can post directly.
A Community For People Who Buy, Sell or Collect Antiques, Collectibles and Art
Brevette in French means patent.
I couldn't find any company with the name Brevette SGNG.
The reason I mentioned photography is I bought this from an estate that was owned by someone very heavily in photography. Someone on another site mentioned what they thought these were, but I wanted someone with a "fresh" perspective.
Thanks for the link. I'll try and use the contact info.
I am not certain people see my posts or links sometimes, but it would be helpful to take note that the correct letters are SGDG, as mentioned in the Wikipedia link above.
You are "coming in loud and clear" !
I deleted my erroneous replies; don't want to confuse people.
Whatever they are they were made in France between 1844 to 1968.
The mystery continues....
What are the dimensions? Do they open? Could you show you, if so?
Oops....yep, there they are!
I think I have found it.