I find that the RPCycs cut off at 1960. By publisher and author expressed intent. Like a certain freight car group.
There is no information about freight car lives beyond 1960 in images or narrative. Not even a hint.
If a researcher seeks 1960's information on old freight cars, one must build on an RPCyc article with additoinal research.
Certainly Rapido used all available resources in their product research. I would surmise that we might see more USRA-derived boxcars from Rapido. As prolific as they are, they do not mind some tooling commonalities. I have no inside information on this.