This slide rule has no maker's name. It has a patent number in the well, DR Patent 173660. Ron Manley, on his website presents an identical slide rule along with a convincing argument that this rule is an early Nestler. Another identical rule can, however be seen on the International Slide Rule Museum website originating from A.G.Thornton. I received this rule from Australia reputedly from the estate of Professor Allan G.Bromley known for his research concerning Babbage's Calculating Engines. I can't prove that this link is real. The slide rule came in a box marked J.Halden & Co, 8 Albert Square, Manchester. Perhaps Halden sold Nestlers at one time although the A.G.Thornton connection may be more likely. 

Nestler System Rietz. D.R.Patent No.173660.The scales on the Halden Rule preceding this are identical to those on this rule. The style of construction of both is the same. This rule has a K Scale and a Log Scale added and has a larger stock. 

Albert Nestler No.3. This slide rule has no manufacturer's mark, however its box is marked Albert Nestler N0.3 and the rule does fit the box very well therefore despite the fact that Nestler N0.3s pictured elsewhere are of a different rule I am keeping this with my other Nestler Rules until it is proven not to be a Nestler or otherwise. It is an unusual rule in several ways, it has Soho style scales and has been designed without a curser rail which would normally indicate an early date of manufacture. The tables on the reverse are in French. 

Albert Nestler No.3. This rule is labelled as a Nestler 3. 

Nestler No.9 

Nestler No.11 M 

Nestler No.11 ZR 

Nestler No.12C 

Nestler No.14 R/1 

Nestler Kiel No.20. 

Nestler No.21. 

Nestler 23R. The tables on the reverse of this rule are in Italian. 

Nestler 27, Prazision long scale Slide Rule. 

Nestler 40. 

Nestler 41. 

Nestler 14/52 

Nestler 29/52 

Nestler SchulRietz No.9/53. 

Nestler 123. 

Nestler 210. 

Nestler 218, Darmstadt. 

Nestler 232. 

Nestler 238 

Nestler 239 

Nestler 250. 

Nestler 251, Alpha 

Nestler 281 Geometer. 

Nestler 290. 

Nestler 330, Chemiker. 

Nestler 370 

Nestler 439, System Jakob, for Reinforced Concrete Calculations,Date Code 1260 (December 1960). Scales cm,Yh(Kx) // K,A [B,R(Fe),C] D,Yh(m)  Yh(Kf) [[sin,sin.tan,tan]]. Sourced from Croatia. 

Albert Nestler Lahr, Friedrich Haver Papierfabrik, Thiergarten bei Ohlau, D.R.G.M.432634 