“Deposé Pratique”

Data:

• Slide rule “Deposé Pratique”, found in Switzerland.
   
• Type: Mannheim
   
• Material: Bakelite (?) of yellowish color.
   
• Dimensions: 150 × 30 × 3 mm, Weight 16 g
   
• Scales: 15 cm/ A = B C = D, length of scales = 123 mm
  It is unsual that the cm scale spans the complete slide rule. On most slide rules the cm (or inch) scale is surrounded by some blank space. Meine van Essen
   
• Cursor made of steel and celluloid.
   
• On back advertising: “ESCHER-WYSS” and “ZURICH-SUISSE”
  Escher Wyss & Cie. was a Swiss industrial company from 1805 to 1969. Andries de Man
  Maybe the production date can be narrowed down by checking the records of other companies advertised:
  - Cie de Fives - Lille - Ch.Abel -Paris
  - Philip S Smith and Co
  - Telegraph Condenser Co Ltd.
   
• Remark: Note the circular intendations on the slide
  The holes in the slide would have contained rubber rings. Fred Stahl
  The are some remnants of rubber in the rings. Jacques Perregaux Stahl
  Other specimens of this slide rule have also lost the rubber:
  - Tina's French Slide Rules
  - Worthpoint
  Andries de Man

Questions:

• Maker?