Model T clocks, by Stewart and Clark of Chicago were actually being made by Seth Thomas, with the “Rim Wind” Phinney Walker patented method

Some 1909 – 1910 cars had clocks called out on their build sheets. They were without exception supplied by Stewart and Clark of Chicago, the same company that supplied most speedometers in the years that Ford supplied them as standard equipment on the Model T.

The typical unit furnished in 1909 – 1910 is a “Rim Wind” using the Phinney Walker patented method, with the mechanism actually being made by Seth Thomas Company. The Seth Thomas clock works was  one of the most respected clock makers in the nation, based in Wolcott, Massachusetts, and by the Model T era occurred, it was over 100 years old. 

https://modeltfordfix.com/t-time-ticking-through-a-clock-mounting-project/