I kind of doubt there would be a stamp on a barrel indicating Stainless Steel ("acier inoxydable" - more commonly "acier inox" or "canon inox") except for the usual advertising logos on the barrel. There isn't a separate stamp for Steel or Damascus.

There are Stainless steel barrel makers in France. Personally I'd prefer a nickel plated barrel for use on salt water.
http://www.armurerie-grand-est.fr/produit.php?id=622
https://armurerie-au-saint-hubert.fr/brand/56-rainier-arms

Baluch are not Brahui, Brahui are Baluch