Post ww2 Dutch submariners uniform parts

[Antipater]

These pieces belonged to my grandad who was an submariner in the Koninklijke Marine (Dutch navy) in the 1950's, he apparently was in the Suez canal during the "Suez crisis" (I have no proof he was there besides his stories).
I was wondering if I could look up his service number and get some info on his service, if anyone can help I'd greatly appreciate it.
Sadly the rest of his uniform was stolen sometime around the late 1970's - early 1980's.
Any form of help is appreciated.





hard to see but looks some kind of marking