Dear All who have replied to my query. Many thanks, the response is much appreciated.
I don't know how to reply and thank each of you individually so I will reply, clarifying what I already know and what I need to know if that is OK.
David OWEN was my Great Grandfather, he was born in Wales, `14th July, 1859 in Davies Row, Michaelstone Lower, parents William and Mary Ann (Phillips). I have his Birth Certificate. He was their eldest child. His sister Ann was born in 1861.
In the 1861 Census, he is not with his parents but with his maternal Grandparents, Thomas and Mary PHILLIPS, at Ty Mewydd Loughor, Carmarthenshire. David's parents William and Mary Ann were at 15 Davies Row Michaelstone Super Avon with his sister Ann (0) and ? his G/father David Owen (60) and ? an Aunt Catherine (16). This is feasible as children often went to live/stay with Grandparents etc, esp. as there was a new baby in the house.
Despite spending many hours going through records, I have been unable to find him in the 1871 Census or in any shipping records to Australia. (Someone from Wales on this site thought he might have come out as a Seaman aged 16, I'm not convinced of this). Ann and George were his siblings and he also had another brother Ronald who didn't come to Australia, instead resided in Wales, but was the Chief Engineer on the Ship the Queen Mary and thus visited his siblings often.
The next thing I have been able to find out about him was when he married
Arundel Francis Howe, 1882, and I do have the info about their children and the 1903 Electoral Roll
So for now the most important thing I need to find out is where was he and who was he with from 1861 to 1882 and when and how did he come to Australia. Once I have this info I will continue with rest of the story. I appreciate all the info I have received and will collate that in the meantime.
Many thanks once again.