Alan,
Your mention of the LANCASTER surname caught my attention. I have in my database FPOC LANCASTER's from the MD/PA area who migrated to Ohio and married into my ADAMS family lines. Perhaps they connect to your LANCASTER folks.
My LANCASTER's start with an David Isaac & Rachel LANCASTER both born in MD ca 1785-1790. Their son Elias born ca 1809 in MD met and married in Urbana, Ohio Melinda ADAMS, 11 Dec 1837. Elias & Melinda had nine (9) children, all born in Urbana, Ohio, Thomas, Mary Jane, Elizabeth, William, Isaac, Susanna, Joseph, John & Eli.
My thought is that these LANCASTER's from MD could have stopped in PA on the way to Ohio and they could possibly be realted to your LANCASTER's in PA.
I'm willing to share my LANCASTER information to determine if there is a connection.
Thanks for your consideration,
Art Thomas