On the 1830 census (Campbell Co. was formed in 1828), there were two Brock households: Henry and John. Based on information in the 1850 census, both were born in SC, Henry in 1802 and John in 1805. Both remained in Campbell Co. for the remainder of their lives and both left wills. I suspect they were brothers, but they may have been cousins. I am descended from Henry through his son William M. and have considerable information about the descendents of both Henry and John, but have very little information about their ancestors.
Two other Brock households were on the 1840 Campbell Co. census: Thomas H. (b. 1800-1810) and William (b. 1790-1800). Neither is on the 1850 census, and I have not tried to locate them elsewhere.
I will send a file to your e-mail address as soon as I can prepare it (my job is such a hindrance to my genealogy!).