Accessory odometer style Shifter Knob

[GearHeadDiver]

Im looking for any information on a vintage aftermarket shifter knob.
1930s?

Round (non spherical) shifter knob with inset numbers, similar to an odometer.
Ive been told it was to keep trackof milage or oil change schedules.?

Any help, insight or documentation would begreatly appreciated.

Thank you

Any

 

[TerryOH]

I saw one on the auction site not long ago.