The set also includes all the other grabs and the roofwalk, too, which is also reverse of what's normally available due to the ladder issue. I had bought the kit I have thinking it was a complete kit, but it turned out to just be the shell. I had another kit that I completed as a commission for the Brunswick Railroad Museum, and I really liked how it turned out... I'd like to finish the other one.
When I last looked at the JnJ site, the wagontop caboose was not listed as being available. I'll have another look.