French switchboard - can anyone tell me what it should do

[Gravityisahat]

I am an unskilled collector of telephones based in the Uk. I particularly like old curiosities like this that are nearly dead. Can anyone tell me I should expect this to do and what connects to what? There are various clues etched into the wooden case but unfortunately I have not been able to find a wiring diagram and the acronyms are clearly French. It appears to have undergone some crude revisions over the years with wires cut and resoldered possibly to revise its functionality. My usual approach to this sort of project is trial and error but in this case I can guess so little I am flummoxed. Can anyone indicate the most likely port for the operators headset and where the battery connects. Most useful would be a translation of the etched acronyms but any thoughts at all would be much appreciated.i have more pictures if that helps.

[FABphones]

Looks to me like an Intercom Switchboard. Could you put a close up of the nameplate so I can read the info there. Might be a Picard-Lebas.

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EDIT:  plate enlargement added

[FABphones]

Bingo!
Thanks for the enlargement teleplay - I'll pat myself on the back there. I may have little knowledge of American and Canadian phones but my European phone knowledge isn't quite so poor.   

Could you add a photo of the outside left side? Just wondering if there are any signs of former attachments.

[RB]

Gonna take a lot of work to get that one goin again.
good luck on that one.
Interesting box.

[Gravityisahat]

Hi

Thanks for the comments - a few closeups of the acronyms if anyone can help.

[RB]

The green and brown twisted wires are your extensions.
There are 4...left.
The 2 contacts on bottom, are prob batt connections, guessing, not sure.
A couple pics with the fuzz clipped off some wires, and a closeup of the socket backs will help to identify things.
you shud be able to hook a magneto to one of the green/brn pairs, and drop one of the signals. quick test.
I don't see a voice coil, so limited in comments there.
That thing has been modified, and some stuff clipped out.

[RB]

you see how the connections go...F something, F something, space, 1...
F something, f something space 2... etc. all across that is the orig config. for the extensions