Can an ID Number be Used for a VIN Number For a 1963 Vehicle?

Yes, its absolutely fine to use an older model vehicle's ID (or serial number) as a VIN (vehicle identification number). In fact, the National Highway Traffic Safety Administration (NHTSA) only standardized vehicle identification numbers to 17 digits in 1981. Vehicles manufactured prior to 1981 still had identification numbers however there was no requirement to conform to the 17 digit requirement; though most already had starting around '77. In the case of your 1963 automobile, the number you see on the title is in fact its "VIN", it's just that it is not 17 digits. The serial number on the title should match the serial number on the vehicle, and once you get the hood open, check for a matching serial number stamped on the engine and/or the vehicle's frame.