So, if you were recreating the reality of a worn out 0-6-0T and a couple captive hoppers working in a gravel pit in 1954 all would be clean and shiny?

What about the steel mill hot ingot or slag train? One trip in service and most of the paint burned off, if anybody was unrealistic enough to try painting in the first place.

Even common carrier shortlines didn't have the money to waste on frequent cosmetic work. Keeping them running on the shooestring they could afford for all maintenance was more than enough of a challenge for them........

Sorry, I've seen to many clean and shiny examples of things that never were in the historical reality purported to be interpreted in many displays. I've seen clean and shiny roundhouses........context is important in telling your story, even if you don't care about historical integrity.

dave

The Rustoleum Rusty Metal Primer is good stuff. Even just the primer coat lasts years and years. No it isn't going to work well under automotive paint, but those are two completely different coating systems and we are smart enough to know what goes with what. If inexpensive effective metal preservation is the aim, then Rustoleum is a good buy.