Owner Of Vehicle Title Cannot Be Reached Have 1979 Mercedes Model 24D The Title From The Owner Has Only 13 Characters. Cannot Get This Registered.HELP

Have 1979 Mercedes model 24D the title from the owner has only 13 characters. Cannot get this registered.HELP - owner of vehicle title cannot be reached

Original title A to Z register 1979 is trying to tilt the title CO. all numbers and letters, what should I do to get this disk. None of the CO has seen or heard of the 13-digit VIN and said the wrong VIN. VIN match the title, the vehicle and Owens manual.