Hi John,
The Sydney Morning Herald of Saturday 4 August 1928 has this to say about his death...
NONAGENARIAN'S DEATH
WEST WYALONG, Friday.
Mr. William Wilson, who died at Barmenman aged 92 years, came to Australia when 14 years old.
He had a thrilling experience in a sailing vessel. The storm blew the masts away, and the vessel was helpless for three days. Mr. Wilson lived at Barmedman for 40 years, and leaves three sons.
13361/1928 WILSON WILLIAM WILLIAM JEAN BARMEDMAN
According to the SMH his birth would have been in 1836 and as he would have emigrated in about 1850 he should appear in the 1841 Scottish Census. Well there is only one census return I can find with 2 Williams and a Jean in the household and that was just on the outskirts of central Edinburgh...
Piece: 6851 Book/Folio: 10 Page: 8 Civil Parish: Canongate
Address: 2, Palace Yards, Canongate County: Midlothian
BLACKLOCH, James M 35 1806 Labourer Midlothian
BLACKLOCH, Susan F 35 1806 Midlothian
BLACKLOCH, Catherine F 12 1829 Midlothian
BLACKLOCH, John M 6 1835 Midlothian
WALLACE, William M 1 1840 Midlothian
WILISON, George M 1 1840 Midlothian
WILSON, William M 25 1816 Maltman Midlothian
WILSON, Jean F 25 1816 Scotland
WILSON, William M 3 1838 Midlothian
WILSON, James M 2 1839 Midlothian
I haven't found any immigration information but maybe with the year information you may have more success, yourself. Try these websites and make use of the advanced search at the Australian Newspaper Archive...
Good Luck.