Don, I wonder if David (1757) is a brother or cousin to Michael Johnson (1770) who lived in Chatham at the same time? It looks to me as if both these Johnson families may have originally been Quaker, and both eventually married into some of the same lines (including Perrys). It is thought that Michael came from VA, but his parents have not yet been determined either. Sarah Johnson(1750), wife of William Perry, has been suggested as a sister to Michael. Or to David.
Do you know the parents of Rebecca Crutchfield Johnson?
Nancy