You will find mention of James Isles in this biog of Thomas Finney, with whom he emigrated from Ireland to Brisbane in 1862.

They were the co-founders of the Finney-Isles chain of shops in Brisbane. James was born in Scotland, but was working in drapery store with Finney when they decided to emigrate. James was recently married to Isabella Jackson from Co Monaghan. Her sister, Sidney Jackson waved them off from the quay. A few years later Sidney followed them to Australia and married Tom Finney. Tom was married soon after his arrival in Brisbane, but his first wife died when the marriage was only a year old. If you email me direct, I can put you in touch with some researchers of the families.