@black_marketeer
If Tiffany's consign a designer for a piece their initial usually is placed in the copyright ©️ symbol especially from Mexico City.
It would take a great deal of time to go over each Tiffany mark here and this is something you can do in your spare time.
Just remember a Tiffany's mark will be a clear, consistent and clarity mark. Something counterfeiters just can't grasp.....yet.