The June auction of the Schlegel auction house in Berlin brought one nice surprise for collectors of Czechoslovak stamps and stamps of the German occupied territories. A miniature sheet, which was issued for the national exhibition of postage stamps Bratislava 1937, was offered for sale and subsequently sold at the above mentioned auction. Some of these miniature sheets were overprinted by the local Nazis with the text "Wir sind frei!" and a swastika after the Sudetenland forcibly seceded from Czechoslovakia in 1938. The miniature sheet also contains a commemorative stamp Reichenberg 1 (Liberec), October 8, 1938. The authenticity of the miniature sheet and overprint is confirmed by the Brunel photo certificate.

Probably inadvertently, one sheet was overprinted upside down, which makes it unique and a rarity of the first order. This exceptionality was confirmed at a recent auction, where this sheet reached € 2,600 plus an auction premium, although the starting price was only € 1,000.

Many miniature sheets Bratislava 1937 were not overprinted - allegedly only 350 pieces. This in itself makes them an ideal investment product, as there are thousands to tens of thousands of collectors who collect postage stamps from this area and period, especially in Czechoslovakia, Germany and Austria. Just for comparison, the original sheet without any overprint has a catalogue value of approx. € 0,6  and a market value max. € 0,4.