Looks like it may have started life in a larger truck as several had speedometers very similar. I think I have a similar one out in the garage that may only go to 80 as I am planning on using it in my boat tail roadster and that car doesn't need a very fast speedometer.
It's a Stewart Warner 509N. Particulars are in here......no vehicle application though. https://www.jalopyjournal.com/forum/threads/sold-unusual-1930s-s-w-100-mph-speedo.1043900/ @titus posted one in this thread.....if it was his, he might have some insight. https://www.jalopyjournal.com/forum/threads/stewart-warner-pictorial-timeline.668982/page-3
The Jalopy Journal
