Hi Glenn, This is a website that has death and cencus records on many of your Sitta family. Yes, it appears that Josef Sitta is Frank,s brother, but it looks like all the children were born in Texas. There parents were born in Europe, or Austria. The father, Frank, may have had a brother named John, or at least a close relative.

http://pilot.familysearch.org/recordsearch/start.html#start

http://www.familysearch.org/eng/default.asp

Good luck.