There is still more to learn about the official usage of these cards, so I'm not going to speculate too much about this one. Since there are no auxiliary markings to suggest otherwise, one can assume that it indeed was sent via airmail (six cent rate) on October 29, 1964 as a false-franked official use. The November 2nd reception docketing on the reverse side would tend to support this assumption. Similar obsolete surface-rate cards have been discovered used in a similar fashion. I think that all usages of this type discovered thus far have been by the Department of Agriculture.
Another interesting thing about this card beyond the usage is the fact that it is also the 'Thin Dividing Line at Bottom' variety for this issue. Supposedly most of the used cards of this type all surfaced in one area of the continental US - Certainly not from the Alaskan Territory!
Place mouse on image to see the reverse side of the card.