Stamp and Revenue Stamp Patent Information, circa 1850's-70's, two massive three-ring binders housed in one carton containing a few hundred items all regarding patents related to stamps, revenue stamps, production of same, printing inks, papers, methods of separation, etc., some are printed copies of patents from the U.S. Patent Office, a few are the actual formal government patents, assembled by Sol Altman and worthy of very careful examination by a philatelic researcher, good-very fine lot, invaluable to the serious philatelist