Hi Kay

Just checking , the Onchan family is not yours ?
Had a look at the UK census online , a good site , you can search by name , get all of the Thomas Cowins with variations of all ages , where they were at Census time and where born , pay nothing until you find who you are after...........but could not find him. Suspect they are listed by strange name , like the one you found !!
Will keep looking. Do you know which son came to Australia , will track him done for you

Cheers
David