original late 1880's american made stamped heavy gauge steel interior residential "ceylon" pattern doorknob backplate designed and fabricated by the p. & f. corbin co., new britain, ct. the heavily ornamented backplate with deeply incised detailing contains traces of the original copper-plated finish. the pressed and folded wrought brass thimble or collar remains intact. measures approximately 5 1/2 x 1 1/2 inches.