A rare 1969 Shelby Mustang GT500 with a mere 8,531 miles on it will go up for auction next month.

One of just 1,000 ever built, the GT500 belonged to Larry Brown of Centre Hall, Pa., who passed away last year and left a diverse collection for auction, Yahoo Autos reported.

The unrestored car, which is listed on the Ron Gilligan Auctioneers website to be sold on April 25, has a 428 Cobra Jet engine with a four-speed transmission. The auction listing describes it as a "time capsule," noting that it still has its original paint including the GT500 decals.

When Brown purchased the car on May 9, 1969 for $5,245.97, the vehicle had a registered mileage of 1,665. In September of that year, Brown had the door glass adjusted, which marked the last time warranty work was recorded for the vehicle. He apparently stopped driving the rare car altogether in 1979, keeping it in his garage ever since.

According to the auction listing, the car was checked by Brown's mechanic about three years ago and "worked fine."

The meticulous owner was known for not driving the Mustang in the rain and not even washing it with a hose for fear it would rust.

"Mr. Brown was apparently very particular about preserving his car--note the mud flaps to protect the rear quarter panels, fine wire mesh to protect the radiator from bugs and debris, and Ford dealer accessory door edge guards," the auction listing described.

Internet skeptics have called the car's nearly total originality into question. Dane Hooper, who is helping to manage Brown's estate, clarified that the tires had been changed but noted that the production line wheels are original.

The GT500 could fetch a high price at the auction block next month, according to Yahoo Autos. Similar vehicles with more mileage have gone for more than $100,000.

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