I would be interested in trying to see if we tie together somehow. As I have posted, Rohauer isn't that common of a name. I think they are all tied together if you back far enough.
My mother's name was Rohauer, she was born in 1931, her father was Elmer was born in 1903, and his father Joseph was born in 1867. All were born in Buffalo. I know Elmer had at least two brothers, George & Raymond. I'm not sure of Joseph's brothers as I cannot find a census with him in with his parents even though I know for sure he was born in Buffalo (I have his death certificate) and stayed there. Joseph may have had brothers that others Rohauer's have descended from. Has your family line all been in Buffalo?