There’s some confusion about there having things like a 1990 factory original cobra Mustang convertible? The name “Cobra GT” was used on Canadian Ford Mustang brochures and other marketing material. The term Cobra GT was a direct replacement for the word “GT”, in fact Canadian Mustang GT owners have “Cobra GT” on their registration papers and window stickers.
This is most likely a product of marketing or some sort of brand/trademark issue. Other than metric speedometer or possibly day-time running lights – these are NOT any different than the GT counterpart. Some Canadian Mustangs were ultimately imported to the USA which caused a lot of confusion.