Nestler 0430 System Hoffmann Concrete slide rule in box 1955 Germany

This interesting slide rule was made by the Nestler company from Germany. This is the model 0430 made for calculating concrete constructions, the successor to the 43 model. There does not seem to be much difference though, this one is still marked 43 so seems to be a transitional model from around 1955 ,when Nestler changed their numbering system. It comes in the original blue signed cardboard box (some glue residue on the back) It measures ca. 29 cm or 11 1/2 inches long. The slide rule is made of mahogany wood, the slider is made of glass and metal. All parts are complete and it is in working order. The middle part can be reversed for more calculations, 1200kg or 1400kg, both shown in the pictures (no color differences). It has minimal signs of age and use but. Check the attached video on how to work your vintage man tool : slide rule operation instructions!