Mark Jones Antiques has dated this Cartier Silver Notelet Case to the 1930s.

Provenance:
Queen Elizabeth II, from 2002 on the death of her mother.

Norman St John-Stevas, The Lord St John of Fawsley (1929-2012)
British Conservative politician, author and barrister; gifted to him by Queen Elizabeth II…’The Queen Would Like You To Accept This, In Memory Of Queen Elizabeth The Queen Mother’ https://en.wikipedia.org/wiki/Norman_St_John-Stevas.
Thence by descent (and never previously on the market).
Mark Jones Antiques has dated this Cartier Silver Notelet Case to the 1930s.
Mark jones antiques are dealers in fine antique furniture, ‘design’, works of art, and works by the sporting artist ‘snaffles’.
You can view the stock and full dealer information on the Mark Jones Antiques Profile Page