It started with stuff from a box of bits and parts that I got in trade…
And a picture… !(http://i592.photobucket.com/albums/tt7/tigerlillie06/His Stuff/mail10.jpg)
There was no roof for the Bachmann, but I had a spare Kalamazoo one… so a 27-foot car it would be. Short enough to still look good on sharp r-1 and r-2 curves. I built the frame out of wood and Bachmann freight car parts. It will be an early wood RPO rebuilt as a composite (steel frame). In 1912 the US Government enacted a law significantly raising the minimum strength and other requirements of RPOs in an attempt to save the lives of the postal workers. The law was intended to encourage the railroads to switch to all steel cars. Some did, many modified their existing cars, and some basically ignored the law. The law was given more teeth in 1913 and revised again in 1945.
Since I had to cut down the body to fit the roof, I decided that it would be platformless to maximize the inside space. Many wood RPOs were built that way to discourage break-ins and vagrants from riding on the platforms.
An impression of an interior, and Pullman green
The doorless or blind RPO end is to prevent access by unauthorized folks while the train is in motion. Externally steel reinforcing is to strengthen the wooden car body - another attempt to comply with regulatory changes of 1912. It also makes it harder for thieves to simply cut a hole to gain access.