The Eight-cent Prexie
Airmail plus minimum insurance
The minimum insurance fee was three cents from November 1, 1944 until January 1, 1949. Airmail postage was five cents from October 1, 1946 until January 1, 1949, which made an airmail letter with minimum insurance eight cents during this time.
This mailing from the Comet Stamp Service was sent airmail with minimum insurance in January of 1948.