"L Extraordinaire Histoire de la Bijouterie CLERC place de l'Opéra, deuxième énigme résolue"
I see that Jean-Jacques has now posted his version of the Clerc story at his Jewellery and Precious Stones blog. I shared all my material with him and you will see that he has made use of some of it, with ample credits given to yours truly.
On a quick first read, I see he has added several new tidbits, including a full biography of author Michel Clerc, which I much appreciate. As he noted in an email to me yesterday, together we have had quite an adventure.