I just did this repair last week, after removing the speedo, disassembling and counting the gear teeth, I was able to find an .stl file for the gear I needed and 3D printed a new gear.
That is one option, although Pelcan also sells several different gears
https://www.pelicanparts.com/cat/r_944m/elgage_odometer-gears?srsltid=AfmBOopls6qyxM3WINYA3o7k9P2zSFNCRdey Jtu2Awoa6eqqICO6TVOY