Vehicle History Reports for Pre-1981 Vehicles
1981 was a pivotal year for vehicles. That year, the National Highway Traffic Safety Administration (NHTSA) required all vehicles to have a standard, 17-character vehicle identification number, or VIN. Since then, automakers all over the world have adopted the VIN.
Originally, automakers used VINs as serial numbers. As manufacturing increased significantly, more information became available and the purpose of the VIN changed. Eventually, the old, hodgepodge system―one that once assigned VINs anywhere from 11 to 17 characters―gave way to the current formula.
Therefore, most, if not all, online vehicle history report sites offer background info on vehicles made either during or after this landmark year.
VINs on Older Vehicles
If you're interested in obtaining information on a pre-1981 vehicle, you'll have to do the detective work on your own.
Consider querying vehicle collector or classic car sites. Some of them contain active message board or user forums. Most likely, you won't find info on a specific vehicle, but you might get a feel for the general repair history for that vehicle make and model year. You can also check the phonebook for car enthusiast groups in your area that offer some insight on the make and model year of the vehicle you're interested in buying.
Buying a Vehicle When You Don't Have a VIN
Beyond that, certainly consider having a trusted mechanic inspect the vehicle before you buy it. This is a sound move for buying used vehicles of all ages, but particularly for older ones. If you are not buying from a local seller, consider using one of the national, certified-vehicle appraisal companies. They will happily conduct an inspection and forward the findings to you.