The Original Classic Mini Cooper as built in 1959 had no flares on it. The stock wheel size of 3.5" never needed them. As the aftermarket supplied wider and wider wheels, flares became so standard that all the later model Minis cam stock from the factory with flares. The first and most common factory flare for the Mini was the Plastic flare (GAW117) often called the Mini City flare as it was first used on a Mini model called the Mini City. There were a lot of "Special Tuning" flares over the years used by factory supported race teams. The "Sport Pack" flare was the widest factory supplied flare ever produced.
If Looking for BMW MINI (2002 & later) Fender Arch Trim (Flares) an Application guide can be found here