Early in my research, I had guessed that the Samuel Price listed in the 1850 census for Minersville, Schuylkill County, Pennsylvania (my gg-grandfather's brother) was the same person as Samuel Price listed in the 1860 census for Washington, Daviess County, Indiana, based solely on name, age and birthplace. Although every other such naive early-research census match of this type has since been firmly disproved, everything that I subsequently learned about Samuel Price of Indiana is consistent with what's known of the actual brother. I was hoping that, eventually, DNA testing might prove or disprove the hypothesis.
A few years back, a direct patrilineal descendant of the Indiana Samuel Price submitted a DNA sample. Unfortunately, not y-DNA, but autosomal. There was no match, either with myself (4C) or my father (3C1R), although I realize that pairwise matches at this level aren't certain. More recently, I found a 12 cM 1 segment match with a reported descendant of Samuel Price of Indiana (who would be 3C3R to my father). A 12 CM match by itself is only little more than 50% likely to be IBD, but given the geographical disparity between Pennsylvania (where much of my family lived for many generations), and Daviess County, Indiana (where I have no other cousins that I know of, and I almost certainly would), is it reasonable to presume that this match probably isn't just from a common population pool? I should add that AncestryDNA has not turned up any similar matches with other Price descendants elsewhere in the U.S. (or, at least none that didn't have some other, more obvious, connection to one of my ancestral families).
I should also add that the first-mentioned (non-matching) patrilineal descendant also doesn't match second one. The first one also shows no matches with any other of his own paternal cousins, but we don't know that any have submitted samples (it's not a large descendant tree). It's tempting to suspect an NPE in his direct paternal line, but I'm concerned that might be interpreting the evidence to fit the theory.