The complete set in detail

ES50AB
Sc Nr. O37:d14
1957 - Official stamp, compass : Background lined and arc project at right, watermark 'DDR and flowers', on granit paper, perforated 14 - 5 Pfg. ; yellow-green

ES50BB
Sc Nr. O38:d14
1957 - Official stamp, compass : Background lined and arc project at right, watermark 'DDR and flowers', on granit paper, perforated 14 - 10 Pfg. ; blue-green

ES50CB
Sc Nr. O39:d14
1957 - Official stamp, compass : Background lined and arc project at right, watermark 'DDR and flowers', on granit paper, perforated 14 - 15 Pfg. ; dark violet

ES50DB
Sc Nr. O40:d14
1957 - Official stamp, compass : Background lined and arc project at right, watermark 'DDR and flowers', on granit paper, perforated 14 - 20 Pfg. ; olive-green