remarkable early 1870's original and intact passage or entrance door escutcheon designed and fabricated by the metallic compression casting company, boston, mass. the all original and nicely aged cast bronze backplate or escutcheon retains the original swinging keyhole cover. the design patent date is lightly incised along the thimble or collar. the intricate design and detail is truly exceptional. the doorknob backplate is free from damage. excellent example of original metallic compression casting company door hardware.