How do you tell If it is original?

I am not the smartest person, but who would break the bottom of a new one ? Is it etched or just painted on ?

When I wrote the air meter identification book I identified 42 different globes, this one was not one of the ones I ID, but I have no thought as to it being real or repro.

Jack Sim

Yes, it is etched

Thank you both very much for Your time and knowledge.