Hi Moira and welcome to the Forum,
Your first mark is the 1st titre Minerva which guarantees the solid silver fineness of 950. The second is the makers mark belonging to Henri Brille, a Paris goldsmith. His details are below:
First name: Henri
Profession: Goldsmith manufacturer
Symbols: A lyre, a star above
Warranty number: 2774
Prefecture no: 15484
Date of registration: 25 June 1919
place (s) of activity: 75, Paris
Address of the workshop: 1) 59 rue Fontaine-au-Roi
2) 12 rue Debelleyme
Info from: Ministry of French Culture database.
I have read elsewhere that he worked from address 1 from 1919 until 1923. The Ministry of French Culture does not give an end date to his registration so I don't know when your set was made. One of our more knowledgeable French members may be able to give you more information so wait and see what they have to say.