car "storage" underneath the MILW car barge

Ray Wheeler had the great idea that railroads sometimes lost track of cars, and in particular that one or more might have fallen off the MILW car barge during loading and never been "reported". I found this amusing, and since the "water" underneath my car barge is removable, tried it out:

The basic idea is great! A number of details could be improved. For example, I don't like seeing the Kadee coupler trip pin so visible. Also, the alignment of the car doesn't make too much sense. This would be a great opportunity for exposing a model with a super-detailed underbody, placed parallel to the side of the barge. Using scale width wheels would be good here too, so it doesn't look so much like a working model. And possibly spraying it with a textured barnacle color. What are your ideas?