Interesting thread. Like Joe, I have a copy of Long Steel Rail and realise that a lot of the Skiffle, Folk, Blues & Americana repertoire is about railways: Building them, driving them, crashing them, robbing them, but I don't know of any about building the rolling stock.
In the UK (and possibly US) there are many groups of enthusiasts rebuilding and running steam trains as a hobby, I wonder if they have any songs to share?
RtS