We recently picked up all the paperwork, brochures, catalogs, pamphlets, record books, correspondence, etc. of a hardware store / farm equipment dealer in business in the same family since the late 19th Century.  The boxes are spread out here on 25 8' long tables, so there are literally hundreds of boxes to go through.  It looks like the family kept everything because one of the first boxes we looked at has items from the 1870s.