This is a piece of stationery from Burma during the Japanese Occupation. This envelope is a King George VI 1 Anna with an X Overprint in Black on the King's face. It also has the personal seal of a Japanese Officer in Black, & Surcharges of 5C and 2C! It's possibly Unique!
This item is over $100 USD so I will ship it using Priority Mail in the US, and registered mail overseas. This is to ensure that it reaches you in a safe and timely manner.