Lost Jacobs in New Zealand?

 Looking for a number of Jacobs, that appear to have vanished I have tried various Australian Sites, USA census but I haven’t tried New Zealand.

Are there any BMD sites I can look up, I have a number of names but the 3 I am interested in at the moment are sons of Lewis Jacobs – glass dealer who was the son of Philip Jacobs. Lewis Jacobs lived around the Westminster district and the majority of children were born here.

Clutching at straws I wonder if they followed their cousins to New Zealand that I have been reading about.
It maybe they just changed their first name, but nothing really ties up and short of ordering about 20 BMD certificates to see, my gut reaction  is that they appear not to be on the UK census…..but I may be wrong!

They are also not mention in the JC when all the other children are mentioned in the late 1890s, early 1900s, either died before those dates or married out, lost contact etc. 
They are;
Joseph Jacobs born about 1828, Westminster can find him on 1841 census age 13, nothing concrete afterwards.
Judah Jacobs born about 1834 Westminster on 1851 census as Cigar Maker, no relevant Judah afterwards, there is one in Holborn but not him!
Samuel Jacobs born approx 1838, on 1851 census says he was born in Surrey but they lived in Westminster at the time, not on any other census I can see although there is a Samuel Jacobs from Lambeth married to a Elizabeth Wood, but doesn’t feel right.
Any guidance would be helpful and then I can check off all my other missing Jacobs across Jacob Jacobs and Philip Jacobs lines in New Zealand.[Debbie Bozkurt]

There are no BMD sites available for NZ, but I have marriage records from early times and electoral rolls for 1881 and 1893.
Also a new CD being put out by the NZ Society of Genealogist called Burial Locator.
Maybe I can help with these.
As a member of the NZSG I also have access to their library.
I’m not at home just now so I’ll have to wait until the weekend to start looking up some of the names you have mentioned.[June Keating]