ALRO printing circular slide rule case cicero Gravura 1960 Holland

This small round slide rule is marked “Gravura” N.V. and Den Haag and is double sided. The Gravura N.V. was a Graphic / printing Company in The Hague same city as the ALRO Company was based. It is in good condition with chromium plating on the centre of both sides intact. Both sides show some small signs of use and some age (color fading), but it is still completely readable and functions like it should. The black rim is also intact. It comes in the original leather case that is complete as well. I assume it is from somewhere in the 1960’s and it is made by ALRO (ALl ROund) from the Netherlands / Holland. This model has simple scales on the front and spacial (Cicero) scales on the back for printing to determine Font size. Both sides have a see-through disc with hairline that acts like the cursor. It measures ca 6 cm or 2 3/8 inches in diameter. Check the attached video on how to work your vintage man tool : slide rule operation instructions!