You are researching the origins of this man - ?
"His name as we know it is William Boden/Bowden b abt 1818 Cheshire. Parents are reported as John & Ellen."
You need to identify the source of each piece of information you are giving the forum to work with.
Where do you see an approximate birth year?
Where do you see native place/birth place to be Cheshire?
Where do you see parents names?
What is the earliest evidence you have of him?.....a marriage record?.....name as father on a birth record?....what?
In reply to the above.
We have him recorded on his marriage and death certificate with parents of John & Ellen and origins of Cheshire.
We have detailed records from his marriage on wards nothing prior.
I had suggested in another post that he may have changed his name as these were not recorded prior to 1850. From the details on his death certificate providing the truth was told he arrived in Australia in the 1830's. The family was always advised 1833 but I think it could even be as late as 1838. I researched others mentioning his mate James Cash in 1848 - This now gives us a timeline as to when they were mates providing they didn't meet up whilst serving out his sentence. We have no knowledge if William is a convict, assisted immigrant or free settler. I hope this provides answers to your questions.