Donald, The foremost authority on what you are looking for past away. Her name was Eunice Elliott of Pittsburgh. She left all her research to the Heinz Library in Pittsburgh. From what I understand there are five or six boxes with many small "books" and files that are unindexed so you would have to go there and go through it. However I have some info as Richard married Frances Knox 27,July 1764 at St. Paul's Church in Philadelphia.John and Richard went to Path Valley in 1761 but,Richard returned to Chester CO.Eunice states Richard Jr. m. Mary Harris a daughter of P.V.John's daughter Hannah. Qouting Eunice "We have no knowledge of Frances Childerstone as an adult."Many of the family moved into Ohio Country.Son William stayed inheriting the Path Valley homestead. There is much confusion on P.V.John He had built a fort just N. of Fannet,Springtown,in the fall of 1754. This is technicaly before it was legal to be there.The land was opened in 1755.Some say he left P.V.soon there after to Chester CO because of Indian threats returning in 1761.I don't think that was true.I remember reading of a Presbyterian minister on the frontier mentioning he stayed a the Elliott place in Path Valley prior to 1761.Again my memory...The story goes John came to PA. in 1761 with George ,latter Capt. George of Va. Navy,a cousin.The date for Georges arrival is true but, he came with his brother John not P.V.John. The repetition of names in the Elliot family makes it confusing.John's brother James of Carlisle records start around 1753 and it was known John first lived in East Caln,Chester CO.,I suspect 1753or before, and was a member of both East and West Caln Prebyterian Chuches.John's brother Andrew held land there.I have records on this.Knox is a name found in Ulster and if my memory is accurate. I have seen in the Laggan region of Donegal.John's brother Matthew remained in Letterkenny Donegal. Brother James son John in Loughnagan, Donegal.Many of the early P.A.settlers from Ulster came from this region the other was the Bann Valley. Rambling but, I'm afraid not much help.