Thanks for the information on Abraham Groves. I'll add him to my notes for John Adams.
I didn't know about a Lawrence DNA project, but checking the Family Tree DNA site, I see there is one, with 103 participants already. There is a descendant of Johannes Lorentz in the group, but he isn't even close to any of the other participants.
I don't know of the Iredell Lawrence you mention. There was one branch of Johannes Lorentz's descendants who spelled their name Lawrence, but most of them used Lowrance. Some of each spelling were in IL, but not until the 1830s. I would suspect Iredell is not part of Johannes' family.