MuMa is gradually publishing the collection database on a dedicated web portal.
You can already consult some of the works:

To date, more than 850 cards are already present including the complete works of Eugène Boudin (350 sheets), Raoul Dufy (128), Edgar Degas (48), Henri-Edmond Cross (41) and Albert Marquet (36) ). The portal is enriched each year, in connection with temporary exhibitions and authors who fall in the public domain as Othon Friesz (72 works at MuMa) in 2020.