Bit more about the (two) Glassworks.
Established 1927 as Verrerie Dessaux in Chapelle St. Mesmin. (elsewhere described as a vinegar maker?) but making general glassware and bottles.
1930 bought by Coty and then made their containers, renamed Verreries de La Chapelle St. Mesmin. I have a catalogue of domestic glass ware, pressed glass in four colours Rosaline, Azur, Emeraude & Blank. With named patterns that are quite distinctive. (Pink, green, blue and clear). Trademark CSM. Incidentally they also made piano foot rest as well as similar for heater, radiators and portable stoves - round, triangular and semicircular. Societe Anonyme capital 5 million francs.
1930 Saint Gobain built a glassworks named Saint-Gobain de Genlis for packaging manufacturing. S-G being motivated by their expansion on container ware exploiting automation from 1925.
c. 1934 CSM bought by Saint Gobain. A company was set-up as Societe Exploitation Verriere Beauce-Bourgogne combined with Genlis works. BVB trademark added. Capital 21million francs, office in Paris.
1945 Trademark Duralex for their Heat resistant glassware range.
1990s bought by Bormioli Rocco
2008 Independent as Duralex International (after a period of stops and starts)
The Genlis glassworks closed, possibly as early as 1969 or as late as 2012 but hard to track that down.
The puzzle, was the CSM logo continued or replaced with BVB, seems likely?
I will add examples of CSM designs shortly.