It looks like a copy of a British-made Gillette NEW. The stamp on the underside looks like a hallmark typically found on sterling silver or silver plate. You can research it here and here.
Your English is much better than my French, friend. Welcome to B&B.
Bienvenue à monsieur de blaireau et de lame ! Je crois que mon ami que Scott d'Atlanta a décrit le rasoir bien, il est un competitor' ; facsimilie de s du " célèbre de Gillette les Anglais ; New" ;. Employez-le dans la bonne santé avec les lames de rasoir à deux tranchants modernes.
Thanks all for your welcome.
Unlike gillette new, the blade is completely flat: no curve at all. I am a little scared to use it!
I'm totally beginner.
For the moment I started with a slimboy and tiger blades (since 1 month) with lot of pleasure.