This comes up quite a bit. The Grande used rough sawn (unfinished) lumber for roof walks, but they were painted. I've worked on a couple of dozen cars which were untouched since Grande days and every one showed sign of painted roof walks. I can't imagine where they would not have painted them to preserve. Isn't the word that they switched to Pullman green because it lasted longer? Dick Dorman and I used to laugh about this all the time. He had numerous color pictures and slides from Chione, Maxwell and a entire series from Rasmussen taken from cabooses that clearly show the roof walks were painted. They got a lot of abuse from traffic, weather and soot so they wore fast but were all painted.