out of those 80%, 95%+ were Nazi bring back.
There are probably more pre WWII French guns in the US than in France.
Those that were not surrendered were hidden (buried), and those usually did not make it through the war without major damages.

Guyot started as a Parisian maker but shifted to Belgian imports around the turn of the century. However, it was certainly a high end shop, and I have never seen anything mediocre from them.
WC-