US 1850s Washington  3c red IMPERF. (various) coll. of 12 diff. CACHET AD covers

Very interesting group of 12 different Advertisement covers (Grocers, Watch makers, Hotel, Newspaper, Sewing machines, Agriculture machines , etc.). All showing Advertisement cachets on front and all (except one which is a perf. 3c with grill) franked with imperf. Washington 3c of various types and shades. Some better cachets. Very good group for further study and research.