Home » Mecum July 2015 – Four Flawless Mustang Mach 1 and Shelby GT500KR Fastbacks » 1968 Shelby GT500KR Fastback 21 1968 Shelby GT500KR Fastback 21 Home » Mecum July 2015 – Four Flawless Mustang Mach 1 and Shelby GT500KR Fastbacks » 1968 Shelby GT500KR Fastback 21