[deuce_roadster]

Whizz--I don't buy your theory. If that were true, the factory leaded seams on our old cars would be the first to go. What is more important chemical wise is the valence of the element which also indicates how reactive it is to gaining or losing electrons. When a substance gives up electrons it is called oxidation (Rust, iron oxide a product of oxidation), if it gains electrons it is called reduction. Lead is very non reactive as you note, however, it has no effect on the steel. If subject to an oxidizer (air, water) it would rust whether the lead was there or not. This is Chem 101.