Hi,
If James was born 1845 he would have been too late to have been a convict transported to NSW.

There appears to be two marriages (from NSW BDM)
4302/1875 OSCROFT JAMES SAMUEL GOODGER MARY ELLEN WAGGA WAGGA
3120/1880 OSCROFT JAMES SAMUEL BASSTIAN MARGARET C DENILIQUIN

and the children
21793/1881 OSCROFT CHARLES B JAMES SAMUEL MARGARET C DENILIQUIN
11046/1882 OSCROFT CAROLINE L JAMES S MARGARET C HAY
14515/1886 OSCROFT JEMIMA H JAMES MARGARET C HAY
16429/1891 OSCROFT HANNAH A JAMES S MARGARET C HAY
16876/1893 OSCROFT ROBERT J E JAMES S MARGARET C HAY
3699/1897 OSCROFT MARGARET JAMES S MARGARET C HAY
3641/1899 OSCROFT RALPH E JAMES S MARGARET C HAY

James death
6100/1903 OSCROFT JAMES S EDMUND JEMIMA GRANVILLE

will check for immigration
Kellie