Jason
You must remember that the Baggage was in MofW service a lot longer than either of the two cars that you mentioned.
The coach in the park in Boulder was placed there in what, 1953? It, itself, has been the subject of at least one bombing that I can remember and was next to the RGS short caboose when it was destroyed in the same manner by a few sticks of dynamite (nice folks, those Boulder people). This coach was from the D&RGW and was apparently pulled from regular service to be donated.
The C&S coach was a victim of benign neglect from the late 1930's on and sat outside in various states of disrepair in South Dakota until quite recently. This coach received no care other than a few coats of paint.
You have to compare Apples to Apples, and this ain't it. In MOW service, the equipment is maintained, although modified.
These are General statements (as are yours) and not based upon any inspection of the car in question.
Rick Steele