Doorknobs from the Stevens Hotel in Chicago were once more plentiful. While they can still be found, be sure to watch out for reproductions. I recently bought a set of repro's marked as originals.

Things to look out for:

• poor or blurred detail
• unusual grinding marks
• poor casting marks
• modern pan head screws

I recommend that you always ask the seller if the item is a reproduction. Always ask to see the the back of the knob and the base of the knob. This is usually where you can see the poor quality of casting and grinding. Genuine knobs are nearly perfect aside from wear from age.

Fronts:
 
To the left is the reproduction knob. To the right is the original. Note
the loss of detail on the reproduction and the sharp and crisp detail on
the original.

Backs:


To the left we have the reproduction, to the right is the original. Note
the poor quality casting and no machining on the reproduction. Also
 note the modern pan-head screw. Another thing to note is the
reproduction takes a square shaft and the original takes a round
threaded shaft.