In the early days of the Friends, I had the pleasure to work with 3 gentlemen who retired from the Rio Grande and spent many years working on wooden cars (John Carson, Harry Babcock, Hawley Seeley). They would get very excited if you called those things "roof walks" or "cat walks", They would let you know that they were "Running Boards".
Would be interested if anyone else had the same experiences.
and btw, never use "deck screws" to fasten down your running boards! I got an ear full once from Harry about that.
Bill Kepner