I got my date by using those estimates. The question I have is one that was asked by the previous person in this thread. What is the thing on the treadle leg near the foot pedals. It's clearly make by Wheeler and Wilson but can't figure out what it's used for. Any help is appreciated. Thanks.
Edit: I have taken the piece off and added 2 new photos to the google album to see if that helps.
JorgeInSF