or one wife died & John remarried....
Will need to obtain some copies of birth & marriages,
otherwise you can never be sure.
You don't want to 'adopt' a family

Could start with this one.
Marriage
John Alfred Collier ~ Susan Gwilliam
Year 1904 Qtr Dec Dist: Salford Vol 8d pg 113
The marriage will confirm fathers name & occupation & hopefully one of his siblings was a witness.
You can get the copies of certs from
http://www.gro.gov.uk/gro/content/The cost of a cert is £7 sterling. I think thats about 17 Aus$
Postage is inclusive.
Heading off to bed.
Happy hunting.
Sue