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Keuffel and Esser Model 4055 "Favorite"

• Type: Closed Body Enhanced Mannheim
• Size: 10 Inches / 25 cm
• Material: Mahogany and celluloid
• Scales:
  • Front: A [ B C ] D
  • Back: [ S L T ]
• HvH: 4147

Unit conversions and materials properties on reverse. Serial number 056537.

The serial number suggests a date of manufacture around 1925, but the cursor on this unit wasn't manufactured until 1933. Probably a replacement cursor.