I just spoke with the head of the "First Families of Highland County, Ohio", and a member of the Southern Ohio Genealogical Society.She informed me that by chance, she discovered that Michal Stroup, and his siblings (Martha Shaffer, Elizabeth Sells, Joseph, and Anthony Stroup), had another (older) brother, named George.
She saw a will of George, who died in Washington County, PA.He died somewhere around 1795-1796.He was a "tobacconist" in Hagerstown, MD.His will leaves a solid gold watch to his youngest brother Michael, and his house (which he was apparently still building) to his brother-in-law, Andrew Shaffer.
According to the woman I spoke with, this record is now being kept in Annapolis, MD, in the Hall of Records.(If somebody who lives near there is willing to go check out the information).My understanding is that he died fairly young.This could be why his name was not included with the family tree in the Highland County Historical Museum.That, or the fact that he died before the rest of the siblings moved to Highland County.The woman I spoke with, whose husband is a descendent of one of these siblings, said that she had no knowledge about George until she found this information. But his will makes it seem that he was a sibling of these other Stroups.