A 1960 Ryuku Islands airmail 9c on 4y brown error block of four sold for $11,210 at Daniel F Kelleher Auctions in Danbury, Connecticut on July 14.
The top two stamps are missing the 9c surcharge.
The islands (of which Okinawa is the largest and best known) were annexed by Japan in the mid-1800s.
Following the second world war they passed into US control until they were returned to the Japanese in 1972.
Stamps were produced under the US administration from 1948 until 1972, when Japanese stamps became valid.
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