15 Fr. University of the Saar country, center piece from counter sheet on blank cover with special cancel "OTTWEILER (Saar) / 400 years city 16.7.50", in perfect condition, extremely rare and only a few examples known, photo expertize C. Ney BPP "the depicted center piece, as well the stamp, are genuine. The unit. Is in perfect condition. ", Michel 1.200.- undervalued!