David, For some reason, it was VERY difficult to post a reply.
This time it worked.
The only Mathias Feather in the PA20 family that would fit is Mathias Feather (1802-1898) x Sarah Salome Carn (1803-1896) of King Twp, Bedford Co, PA who was the 9th child of Henry Feather and Catherine Messemier. He has his own son Mathias (1827-1903) and a Rachel (1843-1866) but I do not list a Catherine for him.However there is a Mary Fetter (1842-) which commonly could be a Mary Catherine as that was apopular combination name.
Since John George is son of George who was #2 of Henry and Catherine,John George and the younger Mathias would be first cousins.
Sorry for the long delay, but the post followup did not function on many vistits since August.