What are some examples of non-paint marks, and the products used to reproduce them?
For a 70 Dearborn car like you have some examples would be
Paint inspector marks on the fender and cowl cover - used ink I believe
Rotation numbers - Example hood, fender and front #1 cross member - Appears to be paint crayon
Exterior battery panel markings (may include spray can also) and sheet metal markings (before paint applied) - Paint crayon
Misc tightened, adjusted or filled indicators - Paint crayon
Wiper motors, alternator, steering column, rev limiter plus others I can' think of at the moment
- Ink stamped