Sun Hemmi 152 Electrical engineer Slide rule in case 1930 Japan

This early slide rule has no number yet. It has the “Sun” Hemmi logo on the slide rule, on the case and on the cursor side. It the predecessor to the 153 Electrical engineer slide rule and was made before the Second World War, putting in the late 1930’s. On the base it also still refers to the 1923 US patent for the P and Q scales. It has scales on both sides and a heavy duty cursor with straight metal frame. Slide rule and curser are complete and everything is in good condition with clear signs of use and age including darkening from the leather container that is also in good condition (smallest tear on flap). It measures ca. 32 cm or 12 1/2 inches. Check out the attached video on how to operate a vintage slide rule!