That looks to me like one of those 70's cars that would have been weathered to death, except for a fresh 'patch' over the dimensional data and rubbed-clean reporting marks. The ACI label would be fresher, as well as the lube plate stencil.
I've successfully 'taped over' factory lettering with adhesive tape (or good paint masking tape) and weathered a car, then pulled the tape off for those fresh patches where they belong.
In the 70's you did see a lot of new dimensional data painted on cars, and as the ACI label readability was indeterminate, great attention to keep the reporting marks readable even if the rest of the car was a mess.