These HO scale models were scratchbuilt by modeler extraordinaire Clyde King. The cars represent Southern Pacific's first set of five car double stacks, developed in conjunction with American Car & Foundry (ACF). Based on the single and three car sets developed SP & ACF in 1977, SP was also the first with five car double stack sets in 1981. The concept revolutionized the railroad industry, introducing an entirely new type of freight car which would forever change the way containers were shipped by rail. Double stack trains are commonly seen throughout many parts of North America today.
On Clyde's models, note the "flippers" or "shoes", used to secure containers positioned in the upper level, are fully functional, turning to open or close as appropriate. Yes, they really do work and grab onto the upper containers! Quite a bit of Evergreen styrene was used in building these cars. Clyde also made several fixtures (often incorrectly called a "jigs") which allowed him to quickly build repetitive parts for the five car set. Those fixtures are long gone, however. He also used a decal set that was once offered by The Original Whistle Stop (hobby shop in Pasadena, CA). I don't believe the decals are still available, try contacting the store to find out.
Clyde displayed the set at the NMRA/PCR convention that took place in Eugene, Oregon in the late 1980s. He won the Gold Award for his efforts; I'll try getting a photo of the award and include it with this gallery.