CH 1974 W50 vignette INTERNABA Basel - draft and original

Switzerland 1974 Vignette INTERNABA 1974 Basel - Centenarium UPU,
Draft for an Internaba souvenir sheet with portraits of famous men from philately and postal history as well as the final version (SBK W50, Michel Bl. 22),
Bloc cancelled "4000 Basel 7.-16.6.74 INTERNABA Centenarium UPU", Design variant of Werner Christen, Spreitenbach (black print)
with Franz von Taxis, Beat Fischer von Reichenbach, Dott. Roberto Paganini, Sir Rowland Hill,
Print: Wertzeichendruckerei PTT, Bern.