South Vietnam, 100 Years World Postal Union (UPU), October 9th, 1974, Michel Nr SVN 572-574; Three stamps in nominals of 20D (Q:1,000,000), 30D (Q:2,000,000) and 300D (Q:1,00,000) were issued in perforation 12.5:12.
Here is the mint set.
A few of the prepared but not issued stamps were left imperforate and sold this way after the war. Here is the set of these imperforate trial proofs.
Enpreuve de Luxe; printed on cardboard paper.
Single franking of the 20D value on a domestic letter sent from Da Nag to Gia Dinh in 1975.
Multiple franking of the set on an international letter sent from Hanoi to West Germany in April of 1988. Clearly the South Vietnamese stamps were invalid since May 1st of 1975 so the 1988 use in Unified Vietnam must have been philatelically inspired and probably took the cooperation of a Hanoi postal clerk for the favor cancel. Nevertheless a curious item.
Mixed franking of the 300D UPU stamp together wit stamps from the Orchid, Development Aid and National Library sets paying an overall postage of 730D on a rare registered express mail letter sent from Saigon to West Germany in January of 1975. The 300D UPU stamp on postally used cover is very hard to find. Fulda arrival cancels on front and reverse. Frankfurt transit cancel on the reverse. Ex Klewitz.
Very rare registered express air mail letter carrying two full booklet strips of the 3D Mobile Post Office stamps plus stamps from the Allied Fighters, Historical Sites, 100 Years UPU, Ocean Fish and Development Aid sets paying an overall postage of 780D. Fulda arrival cancel on front. The editor has never seen another letter that carries a full booklet as postage. Ex Klewitz.
Registration Nr. 201450