FIAT Mystery Clock

I found this fascinating clock in the Paris flea market a year ago. I have never seen another one quite like it.  It appears to be a either a promotional clock for FIAT, or a dash clock that someone decided to mount on a stone base for display.  I love the art deco bezel with concentric circles, but the intriguing detail is that it has a large winding knob on the front face, implying it was probably a dash clock.  There are no markings on it anywhere other than the face, which bears the name of the manufacturer "Metron" and an address in Torino.  It is a handsome piece that I enjoy in my living room, but I sure wish someone could shed light on what car it might have come out of!

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