It's not a Yuzu, it might be Ugli but probably not, unless it's a seedling.
It might be Gold Nugget, maybe having one or two mature fruit is throwing them out to be big and rough ?
I think this is what EricSC is saying.
The leaves in your pics do look like mandarin X orange, so that would cover Tangelos, King relatives.
What scent do you get when you scratch the skin or crush a leaf ??
It could well be none of the above. Here is a list of historic Citrus vars in Australia.
Every category listed below Citrus, Limes and Shaddocks are now unknown here, not in Citrus research collections. Possibly they could still pop up on old farms or gardens.
That's a lot of lemons mandarins oranges limes and pummelos that have faded away.
https://heritageandrarefruits.weebly.com/citrus.html