![PARAGUAY - 1920 - VARIETY: 50c on 75c deep blue with TRIAL SURCHARGE without bars, a fine block of four with variety OVERPRINT DOUBLE on the bottom pair, further handstamped 'CANCELLADO' in red to invalidate the stamps and prevent use. Unusual. (SG 251 variety, Knietschel #260 & 260c) (PAR/32156)](http://latinamericanphilatelics.com/cdn/shop/products/PAR32156_{width}x.jpg?v=1613661817)
50c on 75c deep blue with TRIAL SURCHARGE without bars, a fine block of four with variety OVERPRINT DOUBLE on the bottom pair, further handstamped 'CANCELLADO' in red to invalidate the stamps and prevent use. Unusual. (SG 251 variety, Knietschel #260 & 260c)