It's all staggeringly expensive but they are going to charge for customer service?
Joke.
Btw for mn1 to register a birth as a UK birth...well...it's over £980 and amnesty says the real cost is more £380. The UK makes it very expensive to register your kids born here as UK citizens too.
Ah, here you go:
Taken from this LSE blog post
http://blogs.lse.ac.uk/brexit/2017/05/25/the-interregnum-11-years-without-free-movement-from-1962-to-1973/