To the best of my knowledge pressed glass was not made in many factories, and apart from Sklo/Imwald impertinence, ONLY VSL ever used the 'Fait en Belgique' mark into their designs.
If it should come from any other factory then it would be a real breakthrough in our knowledge!
Boom made a little pressed glass before the war, (not bowls as far as we know) but AFAIK it was paper-labelled and never marked.
A French factory may have inherited the moulds from Boom in the 1970's (but it's unlikely they were ever used again).
We've also seen a base plate marked rather strangely 'Fait in Belgique'. Since this isn't correct French (or even Flemish), we assume this is one of the Bohemian imposters but can somebody confirm?!