The T.O.L date of your Henry Wickham is the same as my GGgrandfather George Gale. This is the date he and the 300 other convicts on the "Minden" disembarked at Fremantle. George was also on the "Justitia" from 1848 till 1851.
I have been fortunate to trace Gale's marriage in 1856, and all his descendants.
Many convicts were sent on to other Aust penal colonies, e.g.. NSW and Tas.
You may find info about this in Rika Erikson's "Convicts to WA" or "Dictionary of West Australians" at Battye Library, Perth, WA.