For the families that shunned offical records you need to rely on your ability to reason to sort it out or the ability of other researchers you feel you can trust. The family had a strong oral history that was passed down. Usually some of that is exact and some of it is questionable. For those of us who like hard facts this kind of genealogy comes closer to theory than findings. The alternative is to have no family history and lets face it we got here somehow and even the genealogy of Kings has some "theory".
Google for "Ned Sizemore"
http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2005-11,GGLD:en&q=%22Ned+Sizemore%22SurnameWeb for "Sizemore"
http://www.surnameweb.org/scripts/data/database.cgi?surname=Sizemore&file=swlink&report=PageCyndis List for "Sizemore"
http://search.freefind.com/find.html?oq=melongeons&id=2077098&pageid=r&lang=en&query=sizemore&mode=ALLCyndis List for "Melungeon"
http://search.freefind.com/find.html?oq=melongeons&id=2077098&pageid=r&lang=en&query=melungeons&mode=ALL