HuskerN - snip the oversize pins off and drill and glue in some .030" rod - it's fast and easy. I think you'll still have to widen the hitch hole a tad but everything will look lots better...
thanks Jim, that is the solution that I will probably choose. Problem is, the spine cars have a large hole in the hitch plate, so I guess the solution isn't perfect for both the spine and the flats. Oh well, it's a minor issue that can be resolved fairly easily.
My option is to just drill out the hitch plate, I figure its easier to have the flats work for all the trailers, than only a few for those.