Hi Tony,
Seems like you might have more info than me!!

I do not have access to the NZ Archives.
Some of what I have I am pretty certain of, but it is unverified, due to limited finances and lack of mobility. But here is what I have:-
Isaac Eggerton somewhere b. between 6/6/1826 & 14/11/1826. Father James Eggerton, mother Unknown nee Webster (no Christian name given).
Tried & convicted of Larceny at Central Criminal Court (Old Bailey) on 6.6.1840, aged 13years. Sentenced to 7 years.
Moved to Parkhurst Prison.
Arrived aboard the Mandarin on 14/11/1843 aged 17yrs., trained as a Cooper & Shoemaker. Free on Arrival. Disembarked Auckland. (Believe that until he died he still had scars on his ankles from the shackles)
On 16/6/1849 Isaac married ary Kerns, daughter of James Kerns & Mary (nee Breen) at Auckalnd.
1852 - Isaac listed in the "Roll of Early Settlers in Auckland Province before 1852" (pg. 72)
In 1881, Isaac is listed on the Electoral Roll as a Wood Dealer, who owned 3 cottages (freehold) in Coburg Street, Auckland. Land in Coburg Street would have been valuable even in those days, being that Coburg St (now Kitchener St) backs onto & runs parallel with Queen Street, the main street of Auckland. He still owned this land in 1893, as per the Electoral Rolls.
As far as I have been able to ascertain, Isaac & Mary had at least 5 children....James, John (b. 8/8/1854), William (my g-grandfather), Elizabeth & Richard (d. 1866 at Auckland).
I have no idea at this satge what happened to Mary, but in 1875, Isaac married Harriet Walling, a widow, at Auckland.
Isaac died in Aucland on 1/5/1897.
That is it! Not a lot, but I hope that it helps.
I have no idea where Isaac was born, so have not been able to trace this family any further back than him.
Hoping that you can help me break through that wall. And I would really be interested in anything at all that you may have on Isaac, before or after his arrival in NZ.
I am really looking forward to hearing from you.
God bless you
Regards
Lyn