I'd remove the colour infills for the b/w version.
True, C+R marks may be a little too obscure for the general public... the only megalithic site they are guaranteed to recognise is Stonehenge... which most of us would probably think too popularist.
Please feel free to say if any of you don't like either - I won't take it personally.... 12 years in commercial graphics have taught me how to get over it!!