Lee, It didn't bother me either till I tried to find one on-line. Then Mt smacked me right in the face with their fiction.
Mike, The underframe would peek through before I touched it, so now it would be even worse. I imagine the underframe will just be strips of sheet lead with no real detail. (P.S. I'm not carving off rivets :-* )
Jason, You can order just about any MT part, but it has to go through a MT dealer (like Chuck) I have a few packets of stirrups from them along with extra boxcar doors and brakewheels. Usually a whole pack of parts is less than a dollar.