I just re-read your description. I see that you mention an eagle. That is most likely the makers trade mark. Many believe that every time they see an eagle it must be a Prussian / German mark. Here is just a partial list of Belgian makers who used an eagle at some point as their trade mark.
eagle with two heads holding a ribbon in its greenhouses Kaufmann Jules and Sons
eagle with the spread wings surrounded of initial Extra "Al" and "Steel" Lochet Arnold
eagle with the wings raised towards the head Janssen Joseph
eagle two headed holding a ribbon in its greenhouses with the inscription "Trade Mark" Schaeffer & kaufmann
eagle comprising initial "A" in the left wing and "G" in the right wing Francotte Auguste
eagle enclosing flashes Limited company for the manufacture of weapons has fire
eagle looking at on the left with the word Adler Pieper B S.A.(Anciens Establishments)
eagle being posed on a map of the world Genschow Gustav & Co
eagle holding the mark Condor in the beak Kaufmann Jules and Sons
eagle holding a snake in its beak Manufacture Liégeoise of weapons with fire
eagle on a cut trunk Janssen Joseph
eagle open wings Dumoulin Fernand
wide eagle with the wings comprising in the medium of the body initial "the L&T" Dawdler and Theate
crowned two headed eagle Bertrand Antoine
two headed eagle crowned with the letter R in the body Bertrand Antoine
two headed eagle crowned with a star in the body Bertrand Antoine
eagle looking towards the left in a circle Cape Joseph
Just in this partial list, there are some makers that produced more that a few quality guns.
Pete
