Corbin, Reading Hardware, Sargent and Branford Lock works lead the list. This item for sale is a Branford model 182 from 1896 - catalog page attests the lineage.

The two keys operate the deadbolt and latch retract (with BLW stamped in the face - with bird logo) see pictures. At the top of the face plate is a horizontal bar, when pushed up it disables the door knob spindle. Thus, the privacy turn or second key can retract the latch.

Complete lock less strike, side plates. Solid brass installation hardware included. Brass knobs, spindle and knob hardware

included.