How to handle Stac Pac containers!

In the 1970s, Stac Pac containers were jointly developed by the Southern Pacific Railroad and General Motors to better handle their luxuary brand cars such as Cadilliac, Buick and others. These Stac Pac containers were loaded on-board 89-ft flat cars by PC-90 Piggy-Packers. The Stac Pac containers were provided by ATSF, BN, D&RGW, FEC, MILW, PC, RI, Southern, SP, SSW, UP and GM with their respective "ownership" markings.  Here's a pic.  As you may know, Wheels of Time makes this scale model of the PC-90s in HO and in N scales, whiile Trainworx has announced the Stac Pac in N-scale.