Block issue "German Red Cross" with factory watermark and additional red cross over the brown cross in the block margin, postmark "PSKOW-k- 28 3 42", original size approximately 118-160 mm, flawless condition, rare issue, signed E Keiler, Gachot et alia and photo certificate Walter Zirath BPP "Due to the small edition, these blocks are very rare." Michel 6. 500.-