Iridescent gold/clear french (?) perfume bottle with engraved mark

Hi all,
I found a pretty iridescent glass perfume bottle, bought it in France so am assuming it is french. The bottom and the stopper (which is not completely round) are clear glass while the body had a gold iridescent coating. It is engraved on the bottle, I am not sure what it reads, it could be “3L” or “7E” or something completely different.
Does anyone recognise the mark, or for that matter the bottle/style?

Is there a similar mark on the bottom of the stopper?
It is often used to match up the two ground surfaces.

How did I not think of that?? Many thanks denbydump, same mark underneath the stopper. So can this help with dating the bottle? I know that numbering stopper and bottle was done very early on but when did it stop? If it did?