Originally Posted by non-fixie

Thanks for the pictures!

Well, it is definitely a RIH from the Westerstraat in Amsterdam. And ca 1960 seems plausible as well. What you have is probably one of the best bikes one could buy at the time. In those days even the Soviets bought them for their best 'state amateurs'. Here is a list of the 63 World and Olympic champions that rode a RIH.