For confirmation:
Marcus's link to the eBay item jogged my memory. My friend's Lion was also marked in the same way: "Sulfoidol ROBIN" to one side and "Iodone ROBIN" to the other. I am fairly sure that the eBay listing should say "iodone" instead of "nodone".
When I searched for information way back whenever, I found references to the Robin company which is where I got my 1950s date from. But current searches have not found the info this time.
I had also consulted another friend whose son works in the pharmaceutical imdustry and was for several years based in France. Unfortunately, no extra information was found.