Hi Gary, I've been searching through everything i could think of trying to find out more of Mary Ann Dutton and Sampson Willcocks and have made a little more progress.
As we know there is no record of either of them in Victoria after their arrival until Sampsons death Will written in 1881 in which Mary Ann is not mentioned, only their three children Rupert, Ada And Arthur and that got me thinking because i had never heard of Arthur until reading that Will but researching Ruperts and the Letchfords adresses i kept coming across an Arthur Wilcox and sort of dismissed him but he was living in the same area and even at 36 Bank st for a short time and Rupert had also lived at that exact address previous to Arthur, so i began researching Arthur Wilcox and the only one i could find for that period was born in Wallsend near Newcastle NSW in 1875, his parents were listed as Richard (Sampsons middle name) and Mary Ann and i thought well this could be someone else but it was looking positive so then i found his death record, he died in 1945 in Coburg Victoria and his parents on that record are Samson and Mary making it even more likely to be the child of our Sampson and Mary Ann but could not prove it for sure but just the other day i got copies of Arthur Wilcox marriage cert and Rupert Willcocks death cert and it all matched up, on his marriage cert Arthur Wilcox gave his parents names as Sampson Wilcox and Mary Ann Wilcox (nee Dutton) and that he was born in NSW, he gave his address as 241 Mt Alexander rd Moonee Ponds (the Letchfords address) he even signed the marriage cert Wilcox and his brother Rupert signed it as witness Willcocks so the two spellings are deliberate by both, and on Rupert Willcocks death cert Arthur is the Informant and identifies himself as Ruperts brother.
So my conclusion is and i have documentation to show that Sampson and Mary were for whatever reason in Wallsend near Newcastle in 1875 but as yet no more is known after that other than the fact i found Sampsons hospital records from Honolulu showing he was admitted to Queens Hospital Honolulu on the 5th of November 1887 and died on the 14th of November of Kydney Disease, he had been aboard an Auckland registered ship called the "Olive" so i'm now looking for Mary Ann in New Zealand as well as here in Australia. I have found a Mary Ann Willcocks who died in Auckland in 1881 but so far no confirmation.
All the very best