I thought the biggest thing I'd see in a convention center was the tank at SEMA last year, but this rail car is bigger, and quite a surprise. It was part of the train for the opening day of Disneyland, behind the engine when Walt pulled into the Main Street Station at the theme park.

The car is normally on display at Walt’s Barn in Griffith Park, where the Carolwood Foundation restored it to opening day condition

the entire rail car was hand crafted by the Disney craftsmen, the inlay, the structure, all but the windows and the seats. They are both from school buses, or school bus supply parts anyway

These coaches, originally built from the ground up at the Walt Disney Studios, were pulled by the E.P. Ripley on opening day as part of an 1880s style passenger train. Three of the four coaches retain their original wood floors. Half of the cars retain their original roof lettering (“Disneyland & Santa Fe R.R.”), though the Walt Disney Company once insisted (to a previous private owner) that all references to Disneyland be removed as the coaches were renovated. They all contain their original school bus style seats and school bus style windows (presumably purchased from a school bus manufactory, such as Crown). In fact, the experience of riding in the coaches is much that of riding in a school bus: the seats are a little small for two adults while most of the windows open only halfway.

The four coaches ran at Disneyland from 1955 until the mid-1960s, when they were retired except for peak days. They were replaced with open excursion cars better designed to view the recently installed Primeval World. The new cars were also easier to load and unload, as all passengers on the original coaches passed single file through narrow doors—still their original Chinese red—located at the front and back of each car.

In the early 1990s a private collector, Bill Norred, gave the Walt Disney Company a narrow gauge engine in exchange for the four coach cars and the combine. Eight years later, after Bill Norred passed away, his family sold the four coach cars to Rob Rossi, who then brought them to the Santa Margarita Ranch in central California. In 2005, the coaches were re-introduced to the public as part of a fund-raiser for the local Railroad Museum. Subsequently, they have been included in fundraising events held at the ranch for many nonprofits. It is also possible to rent the ranch and the coaches for a private function, such as a wedding.

http://www.discoverlivesteam.com/magazineold/70.html
http://www.ocregister.com/2017/07/12/original-disneyland-railroad-car-from-1955-to-display-at-d23-expo/