So my question is has anyone done it without major sponsors,funding and fame?
Jay, I can't see what fame has to do with it but only relatively wealthy people own aircraft in general.
You have to be unusually comfortably off to afford to give up work for the duration of such a long trip.
You'd have to be considerably more that relatively wealthy to afford the massive costs involved in an avgas fuelled flight to Australia (modifications, visas, agents' comissions, fuel, dash, landing fees, bribes, handling fees, facilitation fees, hotac, bungs, food, presents etc) plus cope with repairs and or maintenance en route.
You'd then need to either double your costs by flying home again or be wealthy enough to risk selling the aircraft in Oz - or not, depending on the market.
OK, some might fund it by selling the family home and ending largely penniless at the end like some round the world yotties do but that isn't the usual way.
If only the wealthy did the adventurous stuff in the past there's a very good reason for it. Big expeditions are very costly, and naturally if you're well connected your route via the Empire staging posts was made easier. Nowadays it takes wads of $$$$ that won't fit even remotely the average person's pocket.