Thank you ever so much for the added information...wahoo onward with my research...John age 54: a wonderful clue for me to follow, as to the vessel Barque Cyrus Butler not sure how I would go about invesstigating that fact, but wahoo again!
If, I might impose on you again...there are two other Charles Cockett's that I found, as well.
1- Charles Cockett found on "New South Wales, Australia Convict Ship Muster Rolls and Related Records 1790-1849"
Location Middlesex, England; Age 20; Arrived in Australia 27 Feb 1837 on Emma Eugenia Vessel
2- Charles Cockett convict, also; trial date lent 1805; Location Kent, England; Sentence 7 years transportation.
Not sure if Elizabeth Bentley included information for convicts in her book, but I would appreciate any help from you on them, as well, if at all possible!
My e-mail address is firstname.lastname@example.org
and again thank you for your time and effort!