Isn't the end skirting the part that is usually left ON these cars when they are de-skirted?
You're right, the set is a joke.
Actually this is something Kato should do - they have plenty of passenger cars they could throw together without causing too much of a stink, they could tool an 85' baggage car or really do an animal car - and then do the flatcars, which they could re-use for other purposes anyway.
BTW, the MTL ad shows one baggage car as a "generator car" with grilles in the side - is this to be modelled our just in our imagination?