Xercules,
My general remembrance is that those were honest and trusting days, in which officialdom accepted that you were who you said you were (I think National Registration Identity Cards [I was NZVM 79 3] were dished out just on the householder's say-so - but of course there would be the Registers of Electors to check against). IIRC, they took my Card off me when I enlisted, and gave me a F.1250. Google/Wiki has a fair bit on the subject.
Your particular case sounds a bit complicated (if you don't mind my saying so) and I haven't a clue how they would sort that one out !
Danny.