I believe that the Bernard stamps were still being used well after 1890.
My hammerless Lefaucheux double rifle in 8 Lebel is stamped 1898 which makes sense as a date and only bears the Bernard marks. The barrels SN is 35321. I guess that is possible that Bernard made those steel barrels much sooner, but certainly not before 1886 when the Lebel was developped.
The EP shown above was used starting around 1897. This was a proof meant for the barrels only, not the finished gun. The seal of Paris was used for the finished gun. IMHO, it would make no sense to only reproof barrels. However, it would make sense for Bernard to proof the barrels before delivering to another tradesman or before exporting the barrels.
Best regards,
WC-
