Ruyi 6201 Shanghai Slide rule case 1960 China

This complex slide rule was probably, made in Japan by Sun Hemmi but marketed in Shanghai, China by Ruyi. This model is the 6201 with the name on the side and on the container. It has scales on both sides and a heavy duty cursor with multiple hairlines. Slide rule and curser are complete and everything is in good condition with some small signs of use and age only. The container is complete but peals a little at the sides, still protecting the slide rule well. It measures ca. 32 cm or 12 1/2 inches. Check out the attached video on how to operate a vintage slide rule!