Pullman operated over 3,000 heavyweight passenger cars during the heavyweight era, and their Type 2410 heavyweight "drop equalizer" truck (pictured above) was used under most of them.
Wheels of Time, Micro-Trains and Atlas all make Pullman-style heavyweight trucks. And although I don't know what specific prototype(s) they might be based on, they certainly look enough like the 2410 to work as stand-ins -
