Augustin Desombres is mentioned in one of the book of Schuiten and Peeters as someone who has been in the world of the Obscure Cities. From research of Joseph le Perdriel I know about an exposition that would have been held in the museum of Groningen when the Authorities hadn't cancelled it.

From unknown source I got pictures of a house that resembles a lot with the house of Desombres. The paintings in this museum are the same as in the catalogue of Perdriel... Desombres must have existed!