Great work Mitch!!
One of the things that I've observed about 18th century English engraving is the variation in depth of cuts. Often not only do lines converge to give darker shading but the cuts are gradually deeper. You can really see this in worn areas where the only engraving left are those deeply cut shaded areas. I also believe that they sculpted some details, particularly leaves, using a round bottomed graver. I also like to use hammer and chisel for my main and secondary lines to achieve a vintage look. I use my Airgraver for the details. While cutting detail, I simply cannot see the tip of my chisel clearly anymore even with an optivisor while simultaneously tapping with the hammer. For main lines, I currently huddle over the tip of my chisel with the work at eye level, and have learned to tap toward me, which gives me a much better view of my chisel tip and the cut being made. Again great work Mitch.
dave