Faber-Castell, Aristo, Eco-bra, Hemmi, WN, Concise - Slide rule - Collection of slide rules all complete with case

Collection of 13 slide rules from brands Faber-Castell, Aristo, Eco-bra, Hemmi, WN and Concise, dating to ca. 1960–1970, in good used condition with small signs of aging, with original boxes or leather sleeves. Width: 30 cm. Height: 1 cm. Material: Hout, plastic, metaal en glas. Era: 1900-2000. Brand: Faber-Castell, Aristo, Eco-bra, Hemmi, WN, Concise.