Did a search for odometer repair, nothing. Anyone have a reliable source?
PL
Phil Severence is well known among classic Mustang folk for tach, clock and other instrument repairs. I've happily used him several times. Don't know whether he also does odometer/speedo work.
https://www.phidonrestorations.com/
Palo Alto Speedometer is well known by the local car community in Northern CA. Don't have personal experience with them, though.
http://www.paspeedo.com/