From Robert's Kusan Page:
Andy Kriswalus acquired the tooling from Kusan in 1967 and began producing a line of rolling stock under the Kris Model Trains name. In the 1980's, Williams Electric Trains obtained much of the former AMT-Kusan tooling from Kris. For a time, Frank's Roundhouse produced rolling stock using some of the original molds. K-Line Trains purchased most of the old tooling from Williams in 1985. In 2002, Taylor Made Trucks sold a four-wheel Lionel switcher, as a load on one of their trucks, that was made from the former Kusan and Williams molds. Bachmann Trains (formerly Williams), Ready Made Trains (RMT) and Menards use some of the original tooling today.
Disregard the Menards reference, though, as it is clear the Menards cars are very close or exact clones of the Williams models, Menards has stated they are not made by Bachmann or Williams tooling. It has been mentioned that the Menards cars are made by chinese manufacturer "Golden Wheel".