OK, here's an image... underwhelming as it is...
Both roofs were done originally using the "Liquid Rust" that Model Tech Studios puts out, which is good for what it is, but it only yields one shade of rust and that is on the orangy-side.
So I used the Pan Pastels to quickly give the upper roof a little more reddy-rust. The lower roof was not done.
I did do kind of a swank job on Canadian National reefer, replacing the ultra-thick running board with an etched brass replacement