single early 1880's original "crisscross" pattern antique american residential entrance door mortise lock designed and fabricated by the p. & f. corbin company, new britain, ct. the highly desirable eastlake mortise lock comes with the original thumb twist and/or night latch handle comprised of brass with ornament throughout. the case is comprised of cast iron with a baked-on black enameled finish. the mortise lock faceplate is comprised of ornamental cast brass metal.