DaveCampbell on Family Tree Circles

I am researching the Saycell families from Manchester.
There are 5 brothers there, in the mid 1800s, who were born in various regions of England between 1796 and 1817: Dover, London, Sussex, Bristol and Manchester.There are also another 7 baptisms, almost certainly related.
I have connected them, fairly certainly, to the marriage of William Cecil and Elizabeth Thomas in 1795 Manchester. It is a strong possibility that William is descended from the Cecils of Aughton in Yorkshire as the William Cecil b.1759 Cawood to Leanard and Mary.

I have just come across the criminal past of a John Cecil who I believe to be a 6th brother, baptised as John Saysall in 1800 Manchester. Up until now I had found nothing more on him.

There is a speculative connection to a trial in 1817 Surrey in which a John Cecil was aquitted of larceny. The family were known to be in this area between 1808 and 1811,and at least one other of the children stayed behind, to marry and have a couple of children, before rejoining the rest in Manchester.

He then gets 12 months, at age 20, for stealing a skip of weft in 1821 Manchester and, just over a year later,age 22, is sentenced to death for the highway robbery of a John Williamson, later changed to transportation for life.
John is held on the prison ship Ganymede at Chatham before being transported to "Van Diemens Land" on the "Commodore Hayes" in 1823.

I can find no other records for him in Australia, there are 4 other John Cecils transported around this time and the records that do exist seem more appropriate to them.

There is also a mention of a John Cecil in 1839 Manchester, in the same block of houses as a James Cecil.
Apart from my family, the names Saycell/Cecil don't occur in Lancashire at that time, and there is a known James in the family - my great grandfather, who would be his nephew - and it is in the same area of Manchester as the rest of the family.

And I can't find him in any other UK records