I'm affraid I can't be of much help with Mifflin Co. Shirk's. My ancestors are mostly Lancaster and York Co. I have most of the names of the Ancestors who emmigrated to PA, but I have still been concentrating on my direct family line. I haven't run down some of the uncles.....My Ancestor Ulrich Shirk ( 1663-1739) came to Pennsylvania with his wife, 6 sons and 2 Daughters. I have read accounts that two of his brothers and their family's also came. Two other brothers and two sisters remained in Amsterdam, Holland (they had been deported Sept 29, 1711 from Switzerland). One of the brothers that remained in Holland had a son, Caspar (b abt. 1706). He emmigrated later, 1732, and his decendants migrated to Indiana. It is most likely that your Mifflin Co ancestors are related to one of the two brothers that may have came at the same time as my ancestor Ulrich....arriving Port of Philadelphia Aug 24, 1728. As I said I have not dug into the other brothers yet but I am fairly certain it was Joseph Shirk (Schürch) b. Oct 1669 Sumiswald, Bern, Switzerland, and Peter b. Aug 1676...same location.