antique bronze or brass door knob, vintage heavy cast door hardware w/ original patina

Authentic antique brass or perhaps bronze door knob... heavy cast metal with a dark original patina. A nice architectural art element in the Eastlake, Art Nouveau, or Aesthetic traditions.

This doorknob measures about 2 1/4" across and has a 1/4" square, non threaded spindle socket. It has some dirt and soil down in the cast details from long ago. We didn't clean it.