I cannot vouch for the accuracy of this info (from a Stephenson Index) since I myself do not have the issues referred to, but evidently Railroad Model Craftsman has run plans of the C&NW's 4-6-4 three times: Nov. 1940; July 1962; and March 1959.
Be aware that it took RMC a long while to catch up to the quality of scale drawings that Model Railroader became known for. Even into the 1960s some of their scale drawings were pretty basic.
Dave Nelson
A drawing of the E-4 Steamliner is on display in my blog.
Does anyone know where i can find plans for the C&NW 4-6-4 locomotive? Gary