Neat box! Always loved those panels and boxes. The Post Cereal backstory probably warrants further investigation though. The team name was announced in November 1960, and Post Cereal had enough of a presence in Minnesota to know the name-selection rumors beforehand rather than relying on some guy. Also, if they thought they were going to be called the Minneapolis Senators, why not print that on the cards, rather than just Minneapolis?
Seems more likely the cards were printed before late November--several players had changes made to show a new team on the updated, perforated versions, and those trades seemed to occur in December, 1960. Finally, I do not believe they ever corrected the boxes, instead they allowed orders of complete team sheets that showed the updates.
And yes, Bob Allison was a real favorite in Minnesota too! He wore no. 4, and my aunt thought he was the most handsome player to ever don a Twins uniform. The rest of us were just glad he could hit. Flashed some real leather in the '65 series too, as noted by Vin Scully:
https://www.youtube.com/watch?v=eUQCLfttnxE