A vintage SUPER FLECHET PLUME 65 grammes, HENRY MARTIN CALAIS, FLECHET De Luxe, Made in France Fedora hat. 

There is uniform light fading that appears to come from the inner band (goes all the way around the hat), although the inner sweat band seems very clean. The only measurement I can find is the "4 1/2" that is under the sweat band (pictured). I measured the outside diameter of the hat at about 57.5 centimeters, so the inner measurement is probably closer to 56.5 (size about US 7ish?).

*Approximate opening length measured between sweatband is 7 7/16" (188mm), width is 6 3/16" (157mm) and brim is 1 3/4" (45mm) when brim is flattened.