How old would Udo Proksch be today?

Udo Proksch, also known under the designer name Serge Kirchhofer, was an Austrian businessman, designer, socialite and convicted murderer. A prominent figure in Viennese postwar society, he became known as an eyewear designer, entrepreneur and owner of the famous Viennese confectioner Demel. He was also closely associated with the politically influential Club 45, a social circle connected to leading figures of the Austrian Social Democratic milieu.