hard to find early 20th century ornamental cast bronze "geneva" pattern exterior salvaged chicago two-flat doorknob backplate

single early 20th century antique american ornamental cast bronze "geneva" pattern entrance door backplate fabricated by the barrows lock co., lockport, il. the finely cast brass doorknob backplate contains a large, protruding thimble or collar. the circular opening is used with a cylinder lock. mostly uniform surface. measures 13 1/2 x 3 1/4 inches.