I wonder if MPC chose the symington wayne truck because the person in charge of retooling trucks knew nothing about trains and thought that was a normal truck to model?
Are the plastic trucks that LTI replaced the symington wayne with considered AAR?
In answer to the first question: Most likely. Someone at MPC probably was rummaging through some railroad literature and just stumbled upon that truck design and decided to go with it because it looked modern.
In answer to your second question, the new truck design LTI came out with was not based on an AAR design; rather, it is roughly based on a prototype ASF ride-control freight truck (probably 100 ton). I say roughly because the shape of the open cavities on the truck sideframes aren't as symmetrical in relation to the truck as the real ones are (probably a carryover from the Symington-Wayne truck so that they wouldn't have to re-design the snap-in plastic pickup roller assemblies MPC designed for the S-W truck) and there's too much "clunk" below the roller bearing journals. But it's definitely a much more representative of modern roller bearing trucks than what MPC came out with.
