Central and South America: Argentina with 1930 Zeppelin (blue overprint) 20c. to 3p.60 and (green overprint) 20c. to 1p.80, all handstamped "MUESTRA", 1930-31 Revolution ½c. to 50p., all handstamped "MUESTRA", Bolivia, Brazil 1931-32 Zeppelin surcharges, Chile, Colombia 1935 Third National Olympiad set, Costa Rica, Cuba with values (28) handstamped "MUESTRA", Dominican Republic with values (58) handstamped "MUESTRA", Ecuador, Guatemala, Haiti, Honduras, Mexico 1933 Statistical Congress, 1934 National University Fund Postage and Air sets, 1935 Amelia Earhart Goodwill Flight overprinted "Muestra", Nicaragua, Paraguay, Peru, Salvador, Uruaguay and Venezuela. (many hundreds)