All-
There is a thread on Railwire N about making a working RPO in N Scale.
I was reminded at a train show this weekend that the American Flyer “Mail Pickup Car” which was a New Haven Baggage modified with a larger left hand forward door to accommodate a flapper which kicked out a mailbag when it opened and knocked in the bag off a pickup arm when it closed working off of a pickup shoe on an outside third rail segment for power to the actuating solenoid. This meant the pickup had to be on the left side of the train.
Of course, with most railroads running right handed on double track it meant that the pickup arm would be on the right side of the train in double track territory. On single track if there was just one pickup arm (most likely) it could be on either side of the track according to which was most convenient for the local post office, configuration of the station, tracks, etc..
So the pickup arm could be moved from side to side but I imagine that a car that had to make pickups on both sides at least two sides would be equipped with arms (the leading door seems to be the normal one). The arms and plain safety rails seem to be on the small (2’-6”???) doors and not on the larger baggage-style doors used for loading and unloading at stations.
I think I’ve figured out a way of making a working RPO in N and HO but won’t be discussing it until I work out some of the details….it would be a fun accessory…..at least it was “back in the day” when I had my AF layout!!!
Charlie Vlk