Very rare & unique vintage Ford mustang polarized sunglasses & case

These are extremely rare vintage Ford Mustang Versace style sunglasses I cannot find a match online after hours of searching. They were my grandfathers, and in storage for 20-30 years. There is a tiny bit of fading on one of the lens from where the sticker was (see photos) it does not affect the polarization or the protection of the sunglasses, and can hardly be seen unless a bright light is shined directly on it. Other than that, they’re in very good condition considering their age as well as the case. There are no visible scratches on the lenses. Not sure if he ever wore them or where he got them? He was from Detroit. Questions? Leave a comment below!