[VictoriaHardware]

That may work. Another approach is to "re-apply" them. They probably were not wax crayon- more likely were written with a "paint pen" since they have lasted 50 years now. The Corvette restorers have this stuff well researched. Corvettes were made in the St Louis Plant along with Impalas and pickups.

So get one of the same markers the Corvette restorers use- probably black. Trace the original and duplicate it after your new paint. However, one big mistake the Corvette guys always do is making these assembly markings too neat. Remember, these were written as shorthand by the line workers in a matter of seconds.