I am afraid that I have a completely different opinion. Almost nothing is genuine, although it may have been built by traditional methods. Basically it is just there to milk the tourists, and it is not cheap. It compares most unfavourably in my opinion to the mining museum at Caphouse Colliery in the UK, which admittedly has the somewhat unfair advantage of being free. I took some Australians there and they agreed.
As for the gold panning on site, it is seeded with gold particles every few weeks. You can do real gold panning in many places, sometimes at very low cost.