Hello Lu,
First - many thanks for your time and effort in digging out the surprising amount of information on John Eaton and his family, then typing and sending it to me. It served the purpose of identifying the Duckworth information and adds extra Eaton info to the family history of my friend.
I discovered a Robt Duckworth (27 & a weaver) who sailed from London onboard the "Omba" on Jan 26 1901, bound for Sydney. I then noticed that the passenger who was listed just above him on the manifest was a Mr J Heaton (29 & a shoemaker). That 'rang a bell'! I looked at the 20-odd page family history story I had done for my friend a couple of years ago and found John Eaton, correct age, a shomaker. They had spelled his name wrongly on the manifest.
Robert Duckworth and John Eaton were brothers-in-law. Robert was married to Elizabeth Eaton - John's sister.
I then discovered that a Mrs R Eaton (30) along with a 1 year old William had sailed on Sept 25 1901 onboard the 'Delphic' - destination Wellington. The 1901 UK census showed John Eaton's wife to be Rebecca (30) and a son William (1). [It was handy for me that the UK census was late March and showed the families of both Robert Duckworth & John Eaton - the men left in late April]
At that point I asked if you could find John & Rebecca Eaton in NZ - that would help to confirm that Mr J (H)eaton & Mrs R Eaton were in fact John & Rebecca. You did so

That discovery sadly destroys the whole intruiging story that this thread started on

. Elizabeth did not run off to NZ with the children and leave Robert at home. In fact Robert was in NZ before her. The men presumably went ahead to have a look, find, work and homes before sending for their wives.
Why did Elizabeth Duckworth not travel with her sister-in-law Rebecca in 1901? The answer lies in the parting gift that Robert gave her! By Sept 1901 she was 5 months pregnant. The child was born in early 1902 and Elizabeth then went to NZ later in 1902 onboard 'Britannia' - as previously discussed. The child (Eveline) would have been safer & more manageabe at 9 months than as a new born.
I now believe that the 1907 'Seydlitz' voyage from Sydney to Southampton (previously mentioned) was the Duckworth family on their way back to the UK (Mr R Duckworth, Mrs, Master & Miss). I agree with the 'Engineer' bit, Lu, he woudn't have been working as a weaver in NZ so he may have been employed as some kind of 'engineer' (but not in the strictest sense of word).
I hope you are not too disappointed, Spades! My friend's mum knew her grandma Elizabeth and would have been about 15 or 16 when her gran died. She remembers that the NZ episode was a subject to be avoided and there always seemed to be something of a mystery about it. I will add a couple of thoughts in another post tomorrow.
Malcolm