Stephen, if your lockplates have no engraving your gun is a Quality 1. Quality 2 guns had a "sunburst" in the middle of the lock plate. Quality 3 and 4 supposedly weren't manufactured until 1894 but there are at least 3 examples of Quality 3 engraving on guns attributed to "XXX". The "XX" and "XXX" were all made 1890-92.