~~~ right under our nose and we don't know it.

It's not as though the place was in some remote town in France: it was in a major city and on a very famous street where there were a few well-known casinos for over 100 years of which more than one operated in a single building.

A couple years ago I found a cercle in that very same city that wasn't listed anywhere in the hobby and unknown to the hobby for well over 125 years and I found it in a travel publication while searching for a casino name from another city... which, involved very little effort and the help of Google.

All we may need with this casino is a nacre with a CM monogram or a metallic jeton... and, if I had to guess, I think it would be an educated guess with what we already know in the hobby and compare and I bet at least two collectors would point to the same jeton as maybe being what we are looking for...