I don't know where the office was, but there are three issues of the "Kansas Constitutionalist" newspaper by Thomas Key available for interlibrary loan, on microfilm, from the Kansas State Historical Society.

Take a look at this link for all Territorial period newspapers in the KSHS collection.......

http://www.kshs.org/research/collections/documents/newspapers/t__erritorial.htm

Hope this helps

Dave Goldy
Overland Park, Johnson Co., KS