I have this model, but without branding. Didn't know they also came from Nationaal. But this is a step up from the ones I usually see at flea-markets here, the version with the white knob. The Zinc alloy and plating of these is usually very poor.
"Nationaal" was a brand made by the "Apeldoornse Messen Fabriek". As the name suggests founded in Apeldoorn bij the german Eugen Hollaender in 1931. Beside Nationaal they also shipped the blades under the brands Amefa, Olinda, Somefa, Royal en 'Voor vader en zoon'.
Production of razors/blades stopped somewhere in the 40's , but the company still exists as Amefa and even have a history page on their site: