I would second Richards comments. In O, the Atlas Horizon car trucks would be the closest. The Bachmann ones in HO are the most accurate outside of brass Metroliners I have seen and the first several years had beautiful sprung Faively pantographs. The trucks are also very close to the late production RDC trucks and similar to the ones found under the Atlas Horizon cars. The GSC trucks used under the Congo cars were not the came.