I am pretty certain that the dishwasher in the later KitchenAid Electric Sinks could be interchanged with another KitchenAid dishwasher.
I believe also that the dishwasher in Westinghouse Electric Sinks were able to be removed, and were not physically integrated into the Sink cabinet. I would have to take a closer look at the ones that I have.
It seems that another brand had a dishwasher that was not integrated into the sink cabinet, but I can't remember which, if any.
Mike