South Vietnam, 20 Years World Health Organization (WHO), April 7th, 1968, Michel Nr. SVN 403; A single stamp with a 20D nominal and in perforation 13.5 was issued.
Here is the mint stamp
and here the postally used stamp
Enpreuve de Luxe; printed on gummed stamp paper. Government Printing Bureau Tokyo printed at bottom right.
Mixed franking of the 10D WGHO stamp together with the Friendly Nations of the Free World set paying an overall postage of 65.50D on a rare registered expire air mail letter sent from Dalat to West Germany. Saigon and Frankfurt Railway transit cancels and Fulda arrival cancel on the reverse. Ex Klewitz.
Mixed franking of the 3D Lions International and 10D WHO as well as the United Nations Children Aid and Vietnamese Women sets paying an overall postage of 184.50D (including the red ffee frank for 125D) on a registered international air mail letter sent from Saigon to West Germany in April of 1969.
Registration Nr. 200800