I grew up in Brown County, and am a descendant of Robert Conn through his son, Robert Conn, Jr., the father of my grandmother, Luella Conn Harman. I know of Robert Jr's brother, Richard, but have no particular knowledge of him besides general references in county histories.
My double first cousin, Dr. Louis E. Harman, has researched Robert Conn, Sr., and Jr.(Richard's brother), and probably has more information available on each of them than has anyone else. Lou lives in Universal City, TX, and you might give him a call. I assume he is listed. Lou, a retired Army doctor, is 81, and has some health issues. I've not talked genealogy with him since a family reunion in Brown County a few years ago.
I assume that you have the sketches on Robert Conn, Sr. (there's also one on Robert Jr.) in the 1886 (or about then) History of Brown County. If not, I can make copies for you when I'm in Brown County again (not for a few months -- I live in upstate New York).
There is a Brown County Genealogy Library in Georgetown. I doubt they'd be able to dig up much specific information of value to you.
Good luck on your research, and pass along any information you dig up on Richard.
DON LAYTON