Just one of several MP 70' express box cars used for hauling mail till the mail contracts were withdrawn. This series of cars then went into various uses finally winding up mostly in MOW service as storage cars. Their light weight capacity limited their uses what with aluminum doors and roof. Above, MP 143 being modified at the Sedalia, Missouri car shops. Below, MP 163 in Neff Yard Kansas City, Missouri and MP 183 showing off it's livery.

For modeling purposes, the doors and roof were not painted but were natural aluminum.
Once the metal weathered it took on a fuzzy white color.