Thanks Bacco,
This is more than helpful. I am really VERY impressed. It confirms my expectation of a date before 1900.
I actually know of a "Madame Carnot", but not in my collection. The design of the tin is quite similar, but instead of Princess Alaxandra we have a picture of much older woman who probably is Cecile Carnot, wife of the French President Sadi Carnot (1887-1894).
Do you have a large documentary material yourself or do you find your information in public libraries or archives? I wish I had better access to sources like this.
Once again thank you - and if you find more information about the identity Snelling & Co it goes without saying that I would be very grateful
Kjeld