Have you ever tried a graphite stick, RangerJoe? I ask because you have spent so much time emphasizing the borders and background that they almost overwhelm your nicely proportioned and sensitive linework in the portraits. Perhaps a graphite stick held so that you used it's entire length to make broad sweeps of cover would be an interesting addition to your work. Actually, the stick broken into manageble lengths could work nicely with your shading techniques in the features themselves.
Thanks for sharing