I've just had a chat with Mr G about the old Shalimar flacons that have a small hole drilled through the base of the blue stopper. I understand this was used for a time to feed the thread through when sealing the bottle. It was a design feature that was obviously later improved upon. Unfortunately, neither of us can date these bottles. I *think* I read somewhere that these are very early release flacons, but I can't be sure.
Is there perhaps a basenoter out there who knows?