Food? Water? Unless he was close to civilization at all times and just stopped into taverns to eat.

The book says there were stations every few days all the way around.

I can't speak for non Queensland parts of that map.In the 1900's there was more than a week of walking between even the most basic of civilization (Between mackay and townsville, the A1/Bruce started construction in 1930)

Hardly “unassisted” then.

Unassisted just means you don't have a dedicated support team.