Adjuster Stem

The stem of the Norris Adjuster appears to have changed over the years. The earliest I have has a steel, not brass, turned knob at the end, and the shaft is noticeably thicker than later years. The Prewar A5 with the brass knob was made after 8/1/1927 - at least that is my assumption since the owner stamped that date on the bed. The Postwar has a small metal shoulder or collar just under the brass knob.