Thanks to Alex for sending these pictures. I hope to see one of these someday. Tentatively, I would say this looks like some of the late Thibouville clarinets. (For comparisons with others by Thibouville, start on the Vintage page.) I say this primarily because of the plain sans serif font of name stamped on the instrument. Also the rather key work (with wide and comfortable rings) is similar to those with this same logo style.
Although there is a cursive bit here. This reminds me of the Brittany clarinet.
Left pinkie keys have two posts.
There is a chiselled out part underneath the right pinkie keys.
The throat tone A and G# keys are totally separate:
I think this is a 1940's case.