Here's his photo; I assume it was taken near the end of his life but we don't have an actual date for it: http://i.imgur.com/KtzpD6L.jpg
Thanks in advance for any light you may be able to shed on this.
I'd suggest you start here while somebody else can provide a better insight on uniforms. These are the Dutch Armed Forces archives, if you do not find it yourself do not hesitate to contact them, they're normally happy to assist. http://www.defensie.nl/english/topics/military-history-collections