Rob A,
You are right! It is a great source for inspiration! I scoured the maps this time for examples of the Compass Rose and oddly discovered that there is a pointy, 3-D arrow shape that is used in many roses consistently through the ages. It may appear a little thiner, or fatter, and is shaded in various ways, but seems to consistantly be present. I wonder if it has a specific iconological significance other than to point the direction N? I would attach a copy of one here, but I haven't figured that move out yet.

This Harvard Map series is also a great source for tons of ideas when rendering mountains, walled cities, trees, coastline graphics, and the list goes on! Thank you for sharing this find!
Nancy - Writemor