Well I've been slowly continuing with the D&H caboose, and also working on a L&HR NE caboose. Their's were sided with plywood, and boards on the ends. I bought Midwest birch plywood, 1/64", and sanded it to the point of being translucent. Also got Evergreen scribed styrene for the ends. No pix of that, as I just did one end a while ago. But did try to sand that styrene thinner too. I don't think it worked as well as the plywood.
Back to the D&H hack, I found a Walthers(?) bay window caboose in one of my stash bins. The steps will work, as will some of the endrails. Lucky find.
I need to see about more prototypical ladders, where they go over the roof. Have to keep looking.