Gentlemen - I am in complete agreement with both of you. I appreciate this style  exhibited onmy guns as well as others.
The thrust of my question, or what was meant to be, is:  was this a deliberate style peculiar to gun engravers for a certain "era", or "period"?  If so, does anyone know how long this style was adhered to before changing?
I'm basically looking for confirmation that this was indeed a bonafide gun engraving style, even a movement, if you will. If so, how long did it last?  
I am no art historian, but the "style" that you are talking about was not limited to gun engraving.  Audubon's prints are another example.  I wonder if some of his prints were used as models by the engravers - they certainly would have seen them.  
The Germans managed some rather cartoonish engraving motifs - I wonder if the Basque makers were simply copying a style they picked up from the German guns they were duplicating (like the Merkel OUs).