These Series of 1928 Red Seal “Funnyback” notes were not actually printed until 1933. The print run was just under 2 Million but only 5000 notes released in the U.S. The balance remained in storage at the U.S. Treasury. It wasn’t finally until 1948-1949 that the balance was released in Puerto Rico.
This popular one year type is always in high demand. It seems like the notes come either high grade UNC or else they’re really beat up circs. No middle ground which make this CHOICE AU example very appealing note indeed