South Vietnam, 8D Friendship with Allied Fighters stamps overprinted with new value, April 1st, 1975, Michel Nr. SVN 592; The 8D stamp was no longer useful given that the domestic letter rate already stood at 25D and hence the stamp (Michel Nr. SVN 546) was overprinted in a new value of 25D in red. Since the Government in Saigon fell on April 30th, 1975 and South Vietnamese stamps became invalid after that date it was only possible to use this stamp for a period of 30 days. As a result canceled specimens or specimens on postally used letters are very rare.
Here is the mint stamp.
Mint block of four.
Very rare single franking of the overprinted stamp on a domestic letter sent within Gia Dinh on April 22nd. 1975. Only eight days later the Fall of Saigon occurred.
Here is the official order from the Commander in Chief of the Pacific Forces (CINPAC) that informs about the closure of the U.S. Embassy in Saigon. The flash notice is dated April 26th, 1975 which is four days prior to the final evacuation.
Registration Nr. 201530