? NESTLER 27 Präzision ?

Data:

• unmarked scales, except for L on front and S and T on slide, split in two.
• no screws
• German label
• no brand or type name on the slide rule, but the label is marked “Albert Nestler, Lahr i.B.”
• double-index side cursor
  Looks like mirror image of the cursor on the Nestler 27 in C. Hamman's collection Andries de Man
  The cursor has been retrofitted and probably comes from a No. 28 or No. 37. You can see this because the long tongue on the side window should point to the K scale on the narrow side. The K scale is offset to the left compared to the C scale. The cursor would have to compensate for this. So the long tongue should be on the left side. Andreas Faßbender

Question:

1. Is this really a NESTLER 27 Präzision?
   Yes, it is a No 27 Andreas Faßbender
    
2. What can we tell about the manufacturing date?
   Between 1914 and 1922
   Lower limit because of steel springs inside of the body.
   Upper limit because of missing A.G. on the label (However, it cannot be ruled out that such stickers were also used after 1922) Andreas Faßbender