The first 1966 Shelby GT350 prototype will be sold at Barrett-Jackson

According to Barrett-Jackson, it's the very first prototype for the '66 Shelby built and has been documented as such by the Shelby American Automobile Club. It also boasts its numbers-matching 289 cu. in. V8 and 4-speed manual transmission.

Being the first of its kind and numbers-matching aren't the only special things about the car, though. One of the odd features on the car is the vinyl roof that wraps over the top and down the A- and B-pillars. This was never offered by Ford or Shelby on production cars, but it is correct to the car. It was a test case since Ford and Shelby were considering making it an option. Another unique feature is that this is apparently the only GT350 that originally came with the Pony upholstery, which featured embossed horses in the seatbacks.

After its construction and use as a prototype, Barrett-Jackson says it was sent to a California dealership in 1966 to be used as a demonstration car before being sold in 1968. It shuffled between a few owners, one of whom started a full restoration in 2011. It also appeared at the Pebble Beach Concours in 2015. Barrett-Jackson hasn't listed an auction estimate, but Hagerty values a concours-quality 1966 Shelby GT350 at $255,000. Considering the car's unique features and history, we wouldn't be surprised if it goes for more.