Willys-Overland set up the Maywood CA Plant during the postwar period to supply dealers & distributors on the West Coast. They not only built Aero Willys cars in the 1950's but jeep station wagons and other jeep vehicles, Maywood was closed in 1954 as part of consolidating the operations of W-0 and K-F under the Willys Motors, Inc., operation.,
Unlike Kaiser-Frazer and other car companies that put a prefix or other identifier into the serial number to identify where assembled, Toledo sent Maywood blocks of serial numbers (sort of like what K-F did with the overseas plants) for their vehicles. While some service-related documents show start points for various running changes made to vehicles during a particular model year, there is no indication that I know of on what was sent west.
Maybe Rick Kamen can supply better info.