UYCOO

• Production era - 1951-1980
• Code name - UYCOO
• Type - Interchangeable bayonet adapter for Bellows I /II with:
  • Elmar (I) f= 5 cm 1:3.5
  • Elmar (II) f= 5 cm 1:3.5
  • Elmar (III) f= 5 cm 1:3.5
• Source - Dennis Laney - Leica Collectors Guide (first edition) page 280 per forum discussion [1] below
• Forum discussion
  • [1]