I don't have my material with me, as I am in the office. I'll be heading home shortly and I'll get a document that came into my possession that my father's cousin came by, it is headed Johns family of Truro, it is basically the descendants of William Johns of Crantock, Charles is on it, marrying Elizabeth Darke, and many of my great grandfather's cousins had darke as a second name. I may have got a name or two wrong , as I've been typing from memory but I'll send what I have, (unfortunately I don't have a scanner) . I am sure that Charles had a twin but maybe I have got mixed up.
My name is Scott Johns by the way so I am happy for you to reply to Scott.