So, I just did a google search on "baur banjo" and found some interesting tidbits. The American National Archives has 28 pieces of sheet music available for online viewing/download. Go here:
http://lcweb2.loc.gov/ammem/mussmhtml/mussmhome.html and search for "baur".
Also, the "Canning Banjo Collection" has Baur's personal scrapbook on hand.
http://www.usd.edu/smm/canning.html
Of course, there are the Stewart Journal collections out on the rochester.edu site...Baur is a common contributor to those august pages.