I have an old German Nestler slide rule, mahogany with white plastic (?) overlays. It was probably made in the 1930s. It was my father's, and I believe he used it in college and in his early work as a physicist. I'd like to know the model number and approximate date, but this is hard to find.
The slide rule is very similar to, but a bit more advanced than this one:
http://www.sliderulemuseum.com/Nestler/S403_Nestler.jpg
In addition to what you see in the photo, it has a CI scale in the center of the slide and a K scale under the D scale on the stationary part. Everything else appears identical to the photo linked above, including the screws, the table of equivalents on the bottom, and inch and centimeter scales on the sides that face away from and towards the user, respectively.
I haven't been able to find any references to this exact model anywhere. Can anybody with Old Knowledge fill in the blanks?