When Trade Administrator Nobusuke Tagomi goes to see Machiko, Machiko's GNR flag is shown to be a 50-star USA flag. Regardless of which flag is flown, the USA would not have added two states in this story, so the most recent USA flag that could ever appear in this series would have 48-stars.
When Nobosuke is looking through the refrigerator in Michiko's house, we can see a jar of Hellmans Mayonnaise. Assuming this is in fact our reality, this is geographically inconsistent with the brand marketing because in this scene they are in San Francisco where it is known as Best Foods Mayonnaise. The two companies, Hellmans and Best Foods, combined before the outset of World War II (1927) and from that time forward sold their mayonnaise under the two brand names, depending where it was purchased. West of the Rockies, Best Foods. East of the Rockies, Hellmans.
The Breyers delivery truck Nobusuki passing in an alley in San Francisco in the 1960's ignores the fact that Breyers did not sell or deliver ice cream on the west coast until the 1980's. The alternate universe theme may explain this issue.