Yep an excellent dragon Brian. You don't see half as much pen graphic work nowadays - it has been completely abandoned for vector work
But in truth it has not been bettered by it - quite the reverse in fact , the clarity of removing the unnecessary distracting detail to make a point whether it be a educational /scientific observation or a aesthetic one, a black & white line drawing really can (still !) get it across so much more articulately .
You demonstrate this so very well in this thread.