New looking for old

I'm new here and wondering if there is an efficient way of locating my first and only new car. It was a '66 Mustang GT Fastback VIN. 6F09K221578 which I ordered in a blue color that was Thunderbird only that year. The Iowa road salt was doing its dirty deed and I needed money for a growing family so I sold it in the early '70s. A state trooper friend ran a 50 state check on the VIN through NCIC about 10 years ago and it turned up no results. Does this mean the car no longer exists or it is just not registered for highway use? Any information would be appreciated. Thank you. tfdchief

Thanks very much Mike. Makes me feel much better knowing the blade in my utility knife wasn't once part of my car! Do you happen to know if there is an Iowa K car organization? Thanks again for your reply.