how can I find pivot size on staff when the pivot is broken
Im looking for staff #2802 for elgin size 12 serial#
29316098

Measure the jewel, or pivot hole.
It is hard to measure with a vernier(?) so any good staff with a known pivot can be tried until the correct one is found.

You can measure the remaining pivot if only one is broken. If both are broken you need pivot hole gauges. I may have this staff;

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