group of four matching unornamented 19th century american antique doorknob backplates manufactured by the yale & towne mfg. co., stamford, ct. the solid bronze interior residential passage door backplates contain single keyholes, thimbles and two screw holes for mounting purposes. mostly uniform surface patina throughout. salvaged from a chicago residence built around 1886. measures approximately 7 x 1 3/4 inches. priced for the lot.