The coincidences keep coming in
There's a tree on Ancestry which shows that James Graves, brother, went to Adelaide on the "Marion" arriving on 10 Feb 1849. I was iffy about this as whilst his age at 22 isn't far out, and his occupation was cordwainer - James Hand's in 1841 was shoemaker's apprentice - his birthplace is given as York, (later - but I think this is the transcriber's addition, which doesn't appear in the passenger list).
Iffy until this afternoon when I was tracing the children of Mary Ann (Hand) Messenger. She had a son James born 1814 in Croydon who married Louisa Boyd, and who should also be on the Marion going to Adelaide but
Messenger, James 34
Louisa 32
James 12
Louisa Chillman 10
John 8
Mary A. 6
Arthur 4
Eliza inf born at sea, Jan. 27 1849
If I'm right that James Graves was James Hand, and James Graves on the Marion was Thomas Graves' brother, then James Graves and James Messenger were first cousins. A coincidence that they travelled out to Adelaide on the same boat? I don't think so!
There are 9 trees on Ancestry with the Messenger family who emigrated on them - none of them know that Mary Ann was Mary Ann Hand - there are going to be a lot of Australians grateful to Selina for finding the detail in that 1809 marriage in Linton
David