: Many many thanks! Going to send it to my watchmaker first. Btw it
: is 36mm wide.

Yes, I'd seen that in your original post, which is why I didn't say that I'd managed to find the correct model :) No way would a 10.5 ligne movement fill a 36mm case so completely.

It would be nice to know the model reference for completeness, but I think we're out of luck on that unless someone can turn up another period brochure. At least, with an almost identical model in a different size well documented, there need be no concerns over authenticity.