MY FATHER WAS BRITISH COLONIAL  SINGAPORE RAYAL AIR FORCE  SOLDIER,  I NEED HIS BRITISH REGISTRATION CERTIFICATE I HAVE HIS BRITISH PASSPORT ALSO CIVILIANS PASS ALSO I NEED YOUR HELP

I would like to briefly explain what really my issues are.

My Grand Father was died in Singapore on the year 1960s, I have done all the necessary things to have the extracted death certificate files,even there is not mentioned his British nationality Number 
Singapore ICA mailed be the required document but unfortunately, there are no complete details showing on it.At that time my grandfather has British passport  colony of Singapore, he is having the CPF fund in Singapore and he left  us for our future, i need to extract the CPF amount from Singapore. while applying they are asking to me submit the British document . please ask you to provide the below document copy for My grandfather .. i dont have any original documents now

but i have the all the documents numbe please let me know how can i get the documents